Speech on Pollution | Know How To Write Speech on Pollution from Here

Speech on Pollution

Speech on Pollution: Pollution is one of the greatest challenges facing the world today. More and more legislation on pollution reduction is being adopted by all countries. Governmental acts can not, therefore, guarantee the complete elimination of this issue. The main thing is to make all ordinary people understand the importance of this issue and to make them respect the environment in which they live. Pollution has been a major environmental issue all over the world. To a large extent, it affects humans and other living beings. It has taken the form of the most powerful demon who kills the natural environment quite easily.

Persuasive Speech on Pollution

Environmental pollution includes two aspects, namely environmental pollution and Pollution Essay. In simple terms, the environment means everything that exists, our surroundings and that affects and influences the survival, growth and development of organisms. In other terms, the world is an array of events around it. Pollution implies the existence of unhealthy, harmful substances that create imbalances in the environment and threats to human and animal safety.

Pollution has been one of the greatest challenges affecting the environment and human lives. It’s an environmental issue that people all over the world face today. A variety of dangerous and harmful materials from different sources are absorbed in the atmosphere and cause various forms of contamination, such as liquid, air, vegetation or minerals, sound and thermal emissions.

Smoke and industrial particles from plants and manufacturing are introduced into the atmosphere and cause air contamination. This polluted air is very harmful to the body as we take in the dust. Sewage and other wastes from industries and factories have their way directly to large water bodies (rivers, lakes, seas, etc.) and are properly mixed with drinking water, causing water pollution. Such polluted water (containing germs, bacteria, toxic substances, viruses, etc.) is very harmful to human, animal and plant health (whoever drinks that water).

Nowadays, the world is not quiet due to an increase in noise levels by travel, sound systems, electronic devices, etc. Such voices cause noise pollution and are very bad for the natural stamina of our ears. Excessive and intolerable noise from cars, loudspeakers, etc. may cause ear problems and even permanent deafness, especially in older people and children.

Man-made pollutants from manufacturers and plants, such as hydrocarbons, solvents, heavy metals, etc., become blended into the field as citizens use herbicides, poisons, fertilizers, etc., or through spillage or underwater industrial contamination. Such pollutants, in the form of concrete, liquid or gas, cause soil contamination that pollutes the entire earth. Such pollutants often affect water and air contamination as they are blended into the aquatic environment and some substances create toxic vapors.

Plastic Waste And Its Adverse Effects

Increasing people’s use of plastics is creating tremendous amounts of environmental pollution and adversely affecting natural, wildlife habitat and humans. Thermal contamination is growing due to the high level of use of water as a coolant by power plants and chemical factories. This induces a shift in the temperature of the water in the large water bodies. It is very harmful to aquatic animals and plants as the high temperature of the water reduces the oxygen content of the water.

We have been covered by a dense blanket of waste from all around meaning upside down, bottom down, and from both directions. We’re breathing in waste, but the most surprising thing is that some people don’t even know about it. Large and developed countries are very liable for this elevated level of pollution around the globe. This is the very challenging issue of this planet that needs to be resolved on an urgent basis. However, it can not be resolved by an effort of one or two countries; it can only be resolved if all countries make a hard and rigorous effort on this issue from various points of view.

Regulations for Curbing Pollution

However, several countries have adopted some effective pollution-reduction legislation that is not enough to defeat this powerful demon. This requires joint government action by all countries in order to completely eliminate it. High-level awareness should be spread to the common people in order to make the effort they need. Each and every person in the country should be aware of, and watchful of, this problem, its causes and harmful effects on the living. The use of hazardous and toxic chemicals by individuals, industries and factories should be strictly prohibited by the state.

FAQ’s on Speech On Pollution

Question 1.
What is the main thing that can be done to curb the pollution?

Answer:
The main thing is to make all ordinary people understand the importance of this issue and to make them respect the environment in which they live.

Question 2.
What are the different forms of pollution that exist currently?

Answer:
The different forms of pollution include noise, air, water, land, soil, etc types of pollution.

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Kerala Syllabus 9th Standard Physics Guide

Kerala Syllabus 9th Standard Physics Guide

Kerala Syllabus 9th Standard Textbooks

Kerala State Syllabus 10th Standard Physics Textbooks Solutions Part 1

Kerala State Syllabus 10th Standard Physics Textbooks Solutions Part 2

Kerala Syllabus 9th Standard Physics Solutions Guide Pdf Free Download of Chapter wise Questions and Answers, Notes for the prescribed textbook can yield you great results if you start practicing them from today. Physics is a challenging concept as it involves complex topics, lengthy derivations and tricky numerical. In class 9, you will be dealing with various new concepts, including forces of fluids, gravitation, laws of motion etc.

Besides, class 9 is a crucial year keeping in mind that you will be appearing for Kerala Class 10 Board exam next year. From here on, you will develop a habit of attempting all the questions asked in the Kerala Board SCERT Class 9 Physics textbook. These SCERT Kerala State Board Syllabus 9th Standard Physics Textbooks Solutions Pdf of Kerala can help you gain interest in the subject even if you do not like Physics at all. To make the subject a bit interesting, our experts have tried their best to explain every question with examples and illustrations.

To give you an edge over the preparation of the exam, we have here compiled the Kerala Board Physics Part-2 solutions for that is approved by Kerala Board. Having the online access of the same, these solution helps you in scoring good marks in the exam as the solutions are prepared by a team of subject experts who are well-qualified in their respective domains.

ISC History Question Paper 2014 Solved for Class 12

ISC History Previous Year Question Paper 2014 Solved for Class 12

Maximum Marks: 80
Time allowed: Three hours

  • Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.
  • Answer Question 1 (Compulsory) from Part I and five questions from Part II, choosing two questions from Section A, two
  • questions from Section B and one question from either Section A or Section B.
  • The intended marks for questions or parts of questions are given in brackets [ ].

Part – I
Answer all questions.

Question 1. [20]
(i) Name the two festivals started by Tilak to propagate radical nationalist ideas among the people
(ii) What is the historical importance of the Calcutta Town Hall in the context of the partition of Bengal in 1905.
(iii) Name two leaders who popularized the idea of the Home Rule Movement in India.
(iv) Which agreement signified the reunion of the two wings of the Congress in 1916 ?
(v) Why did a large number of people assemble of Jallianwala Bagh on 13th April, 1919 ?
(vi) Name two prominent leaders of the No Changers of the Congress.
(vii) What is the historical significance of the Lahore Session of the Muslim League in 1940 ?
(viii) Who was popularly known as Frontier Gandhi ?
(ix) State the proposal in the Mountbatten Plan with regard to the princely states.
(x) Mention one cause of dispute between India and Pakistan after 1947.
(xi) Name the independent volunteer military regiments that helped the Weimar Government to suppress the Spartacist Rising.
(xii) Name the agreement signed between Mussolini and the Pope.
(xiii) Why did Hitler’s first attempt at an Anschluss between Germany and Austria ‘ fail ?
(xiv) What do you understand by the term Appeasement ?
(xv) Name the signatories of the Pact of Steel (1939).
(xvi) Name the technique used by the German armies as they swiftly overran Europe (1939-1949).
(xvii) Why was the Berlin Wall erected in 1961 ?
(xviii) Give any one reason why Britain eventually decided to join the EEC in 1961.
(xix) Which Asiatic country has the right to use the veto power in the Security Council ?
(xx) What is the Balfour Declaration ?
Answer:
(i) At the Lahore session in 1940, The League under Jinnah stated that the scheme of Federation embodied in the Government of India Act was unacceptable to the Muslim League. Further, it emphasized the need of territorial readjustments and demarcation of the geographically contiguous units.

(ii) Khan Abdul Gaffar Khan also called as Bacha Khan was popularly known as ‘Frontier Gandhi’. Fie was a follower of Mahatma Gandhi and his ideals.

(iii) According to the Mountbatten plan, the Princely States were given the option of joining either of the two Dominions, which is, India or Pakistan or they might also choose to remain independent.

(iv) The Mountbatten plan regarding the Princely states led to the Kashmir conflict. After Independence, Pakistan claimed Kashmir due to the presence of large Muslim population but the ruler of Kashmir, Maharaja Flari Singh joined India by signing the ‘Instrument of Accession.’

(v) Treaty of Lateran in 1929.

(vi) Italy had prevented Germany rom achieving the Anchuluss in 1934.

(vii) ‘Appeasement’ is a diplomatic policy of giving political concessions to an enemy power in order to avoid aggression and conflicts. The policy of Appeasement was used by France and Britain to avoid war with Germany and Italy.

(viii) Pact of steel was the military and political alliance signed between Italy and Germany in 1939.

(ix) The Military tactic used by Germany during the first phase of World War II to overrun Europe was the ‘Blitzkrieg’ (Lightning War) that required the use of heavy weapons such as armoured tanks and artillery including the expensive use of planes along a narrow front.

(x) The Berlin Wall was erected in 1961 by East Germany’s Communist authorities to prevent mass immigration from East Germany to West Berlin. This wall completely cut off West Berlin from surrounding East Germany by land.

(xi) A steep rate of the economic decline of the total percentage of British exports sold on Commonwealth markets eventually led Britain to join EEC in 1961.

(xii) China, being a permanent member of the UN Security Council has the right to use Veto power in the Security Council.

(xiii) On November 2, 1917, the British Foreign Secretary Arthur James Balfour publicly declared his support for the creation of a separate Jewish homeland in Palestine in a letter to Lord Rothschild, a wealthy and influential Jew in America. This public assertion is known as ‘Balfour Declaration’.

Part—II

Section—A

Question 2.
The conditions for the emergence of radical nationalism developed when Bengal was divided into two halves in 1905. With reference to this statement, answer the following :
(a) Why was Bengal partitioned in 1905 ? [4]
(b) The anger and indignation of the people of Bengal found expression in the launch and development of the Anti-Partition Movement. Explain. [8]
(c) Briefly discuss the role played by the students and women in the Swadeshi and Boycott Movement. [4]

Question 3.
Communalism (1885-1919) posed the biggest threat to the unity of the Indian people and the national movement. In this context, answer the following :
(a) What role did Sayyid Ahmed Khan play in the rise of communal sentiments in India ? [6]
(b) Give examples to show that the communal tinge in the ideas and activities of some of the Radical Nationalists were also responsible for the rise of communalism. [6]
(c) In what way was the Lucknow Pact of 1916 a significant milestone in the history of Hindu- Muslim unity ? [4]

Question 4.
The Gandhian phase from 1919-1922 was marked by various political events which gave rise to popular movements. In this context, answer the following :
(a) Why was the Khilafat Movement launched in 1919 ? [4]
(b) Trace the development of the Non-Cooperation Movement from 1920-1922. [8]
(c) What led to the suspension of the Non-Cooperation Movement in 1922 ? [4]

Question 5.
Many significant developments in the Indian National Movement took place during the course of the Second World War. In this context answer the following :
(a) Under what national and international circumstances was the Cripps Mission sent to India in 1942. State any four proposals announced by Cripps. [6]
(b) Mention three important reasons for the rejection of his proposals. What was the outcome of this rejection ? [4]
(c) Give an account of the revival of the IN A and its contribution to India’s struggle for freedom under the leadership of Subhash Chandra Bose. [6]
Answer 5.
(a) After the Government of India Act, 1935 was passed; the Congress Ministers resigned. The August Declaration of 1940 by Lord Linlithgow too failed to meet the expectations of the Indian leaders and the people of the country. So, the Cripes Mission was sent to India in March 1942 under the leadership of Sir Stafford Cripes to seek co-operation of India to the British war efforts in the Second World War. Japan had become a threat for England. She had conquered Malaya, Burma and Singapore, and had reached the frontiers of India. This victory of the Japanese worried the British. There was external pressure from the U.S. and China on the British Government to make settlement with India in order to seek her support in the war. So, to win the support of the Indians in war and also to pacify them, stopped Cripes was sent to India.

The main proposals of the Cripes Mission were :

  1. Dominion status would be granted to India after the war. She would be free to remain in the Commonwealth or opt out of it.
  2. Immediately after the war, a constitution making body would be set up comprising members from the British India and the Native states.
  3. To join the Indian Union or to stay out would be entirely the choice of the princely states. .
  4. The actual control of defense and military operations during the war period would be retained by the British Government.
  5. A treaty would be signed between the constitution making body and the British Government covering all subjects regarding transfer of power including the rights of the minorities.

(b) Both the Congress and the League rejected the proposals due to the following reasons :

  1. The Congress opposed the plan which aimed at a division of the country.
  2. The power of the Viceroy remained unchanged as he was still responsible for defense affairs.
  3. No provision was made for the people of princely states to send their representatives to the constitution making body.
  4. Self-government seemed to be a long-term affair. Gandhiji condemned it as a ‘post-dated cheque on a crashing bank.’
  5. The Muslims rejected the proposal as it did not ensure creation of Pakistan and fifty percent of the seats for the Muslim League with the Congress in the Interim Government. Hence, the Cripes Mission failed to pacify the Indians.

Outcome of the rejection or the major event that followed its failure :
The failure of Cripps Mission asserted that the British Government was not ready to transfer power to Indians. There was hardly any possibility of a consensus between the Congress and the British. Gandhiji lost trust in the British and his attitude towards them altered. The Congress also felt that the British were reluctant to concede to India the right to self-government. So, Gandhiji launched his ‘Quit India Movement 1942’.

(c) Subhash Chandra Bose and the Indian National Army : When the Quit India Movement was losing its momentum, the struggle for Indian freedom was going on outside India under a different leadership given by Subhash Chandra Bose.

Subhash Chandra Bose had difference of opinion with Gandhiji regarding the Indian . National Movement which made him leave the Congress and start his own struggle for freedom. Bose was arrested by the British Government in 1939. In 1941, however, he escaped from India to Berlin to secure German help for India’s independence, but very soon he felt that Germany was not interested in helping him to achieve his goal. So, he left for Japan to organise an armed struggle against the British rule with Japanese help.

Rash Behari Bose, an Indian revolutionary, was living in Japan since 1915. He wanted to mobilise Indians for an armed struggle against the British. He mobilised the Indian soldiers who were defeated by the Japanese while fighting on behalf of the British army. Subhash Chandra Bose was now invited to lead the movement. He came to Tokyo in June 1943. Ultimately he reached Singapore on July 2, 1943 where he was handed over the leadership of the Azad Hind Fauj or the Indian National Army. Subhash now became known as Netaji, the supreme leader of the Azad Hind Fauj. 40,000 Indian soldiers who had been taken prisoners by Japan now turned into patriots and liberators under Subhash.

Netaji set up the Provisional Government of India in Singapore on October 21st, 1943. Besides himself, A.C. Chatterjee, S.A. Nyer and Mrs. Lakshi Swami-nathan were sworn in as cabinet ministers. This Provisional Government declared war on British and America.

The Provisional Government was recognised by Japan, Germany, Italy, Nationalist China, Burma and Thailand. The Andaman and Nicobar islands were handed over by Japan to the Provisional Government of India and were renamed Shaheed and Swaraj Islands.

The overseas Indians contributed generously with money and materials for the army. Netaji now gave his famous calls ‘Jai Hind’ and ‘Dilli Chalo’. The most famous declaration of Subhash Chandra was ‘Turn mujhe khoon do, main tumhen azadi doonga’ (you give me blood, I will give you freedom). The INA later joined the Japanese army in its March on India from Burma. They crossed the Indian Frontier on March 18, 1944 and the Indian tri-colour national flag was hoisted in Kohima (Nagaland).

The INA captured Kohima on March 18,1944. The Japanese Military command was all praises for the valour and patriotism of the INA. The INA had to withdraw due to torrential rains, short supplies, lack of air support and losses inflicted by the American bombers.

Japan was finally defeated and the INA had to surrender. Subhash Chandra Bose and his comrade, Habib-ur-Rehman, escaped. It is believed that while on their way to Tokyo their plane crashed and Subhash Chandra Bose died. This brought to an end the activities of the INA. ‘

Question 6.
(a) Discuss the process of integration of the princely states with the Indian Union with special reference to : [8]
(i) Hyderabad
(ii) Junagarh
(b) Name the chief architects of NAM. [4]
(c) Mention any four principles of Panchsheel. [4]
Answer:
(a) During the British rule, there were more or less five hundred sixty five (565) princely states covering an area of 7,15,964 square miles and according to 1941 census, inhabited by 93,182,233 people. These princely states were the bulwark of the British power. But none of them enjoyed the attributes of independent sovereignty. After the independence, there were two alternatives left before them either to join India or Pakistan or to maintain their own independent status like before, Sardar Vallabhbhai Patel now headed the new States Department which was created on July 5, 1947. Naturally he was empowered to have talks with the rulers of those native states.

After a long discussion, by August 15, 1947, all the native states except Jammu and Kashmir, Junagarh and Hyderabad had signed the Instrument of Accession to become a part of Indian Union. Most of the princess surrendered the Defence, Communications and External Affairs which they had never enjoyed in reality. The Instrument of Accession thus, brought no change in the internal structure of those native states.

The most ambitious prince, the Nizam of Hyderabad, declared to remain independent from the date of transfer of power. The Hindus of Hyderabad also revolted against the Nizam. The adamant attitude of the Nizam compelled the Government of India to interfere and apply force. The Indian Army was directed to take action and within five days the Indian army took complete control of Hyderabd. In 1948, Hyderabad became a part of the Indian Union.

The Nawab of Junagarh expressed his desire to join Pakistan though a large number of Hindus lived there. They strongly opposed the decision of the Nawab and set up a temporary independent government there. The Nawab fled to Pakistan in 1948 and on the request of the people, the administration of Junagarh was taken over by the Government of India.

(b) The chief architects of the NAM (Non – Aligned Movement) were Indian Prime Minister Jawaharlal Nehru; President of Egypt, Gamal Abdel Nasser; and Yugoslavian President, Josip Broz Tito. The other architects were Indonesian President, Sukarno and Ghana President, Kwame Nkrumah.

(c) Panchsheel or peaceful co-existence was adopted at the Bandung conference. Four principles of Panchsheel are :

  • Mutual respect for each other’s territorial integrity and sovereignty.
  • Mutual non-aggression.
  • Mutual non-interference in each other’s internal affairs.
  • Equality for mutual benefit.
  • Peaceful co-existence.

Section—B

Question 7.
In 1919, Benito Mussolini formed the Italian fascist party and gradually assumed the powers of a dictator. In this context, answer the following :
(a) What were the main features of the Fascist State under Mussolini ? [10]
(b) What benefits did the Italians get from the government in the early years of Fascist rule ? [6]

Question 8.
The 1930’s witnessed the collapse of international order. In this context discuss the following :
(a) The. political and economic reasons for the growth of militarism in Japan in the 1930’s. [10]
(b) The causes, events and results of the Japanese invasion of Manchuria (1931). [6]

Question 9.
The debate on who or what was responsible for the Second World War is still going on. In the context answer the following :
(a) Why did Britain and France follow the Appeasement Policy ? To what extent was this policy responsible for the outbreak of the Second World War ? [8]
(b) The victory of the Allied powers in the battle of El Alamein was a major turning point in the Second World War. Explain. [4]
(c) How did the battle of Midway Island prove to be a crucial turning point in the battle for the Pacific ? [4]
Answer:
(a) In May 1937 to September 1939 when Second World War broke out, the policy adopted by British Prime Minister was viewed as a policy of Appeasement. Appeasement means “acceding to hostile demands in order to gain peace.” This policy was adopted by Britain and France in 1930’s towards Germany and focused on their own economic problems. Neville Chamberlain, Prime Minister of Britain believed that the Treaty of Versailles was unjust towards Germany. Many politicians also, therefore, thought that German aggression was obvious.

Great Britain and France were mistaken in their assessment. On 12 March, 1938, Hitler invaded Austria and annexed it to Germany. After annexation of Austria, Germany demanded that Czechoslovakia should return Sudetenland. Hitler also threatened that if his demands were not satisfied, he would declare war. Hitler’s demands were unreasonable but due to the policy of Appeasement, Hitler’s demands were conceded. This encouraged Germany to be more aggressive and eventually the Second World War broke out.

(b) The Battle of El Alamein – October 1942 : The battle of EL Alamein in North Africa between the Allied and Axis powers occupies an important plane in the course of World War II. Italy, under Mussolini, also declared war upon the Allied powers after the fall of France. Italians had opened battle fronts in Africa with the desire to capture the British colonies in North Africa along with Egypt and the Suez Canal. Italian troops attacked Greece where they faced tough resistance from the Allied powers and finally made a hasty retreat. They tried to conquer Libya in North Africa but could not stand before the British troops who drove them out. The British army took possession of the African colonies of Italy like Eritrea, Abyssinia and Cyrenaica.

In 1940, Italy invaded Egypt. For two years fighting went on in Libya and Egypt. Australia, New Zealand, India and South Africa had also sent their troops in Libya and Egypt to fight alongside the British troops and keep the Axis powers out of Egypt. The control of Egypt by the Axis powers had cut off Britain from oil fields in the Middle-east and from the Suez canal, the shortest sea-route to Asia. Britain struck back at the Italians in ‘ December 1940, sweeping them out of Egypt and back into Libya.

Early in 1941, Hitler came to the help of Mussolini and sent tank units trained in desert warfare under the leadership of General Erwin Rommel, nick-named the ‘Desert Fox’ because of his clever war tactics most effective in a desert region of war. He came to the help of the Italians in Northern Africa. During spring, Rommel recaptured Libya and drove into Egypt. The British again pushed back the Axis forces into Libya. In May, 1942, Rommel broke through British lines in El Alamein, only 320 miles from the Suez Canal. The British commander General Montogomery defeated Rommel’s army at El Alamein in 1942. This victory was very important for the Allies.

The African project of Mussolini thus, failed and proved to be a prelude to Mussolini’s fall. The victory at El Alamein had following far reaching consequences in the course of the Second World War:

  1. Egypt and the Suez canal were saved from falling into the German hands.
  2. The possibility of union between the Axis forces in the Middle-east and in Ukraine was thus prevented.
  3. The victory at El Alamein completed the expulsion of the Axis forces from North Africa.

(c) Midway Island proved to be a crucial turning point in the battle of Pacific:

  1. The loss of their carriers and strike planes seriously weakened the Japanese,
  2. and from then on the Americans maintained their lead in carriers and aircraft, especially dive-bombers.
  3. Although the Japanese had far more battleships and cruisers, they were mostly ineffective.
  4. the only way that war could be waged successfully in the vast expanses of the Pacific was by air power operating from carriers.
  5. Gradually the Americans under General MacArthur began to recover the Pacific Islands, beginning in August 1942 with landings in the Solomon Islands. The struggle was long and bitter and continued through 1943 and 1944 by a process known as ‘island hopping’.

Question 10.
(a) Explain the development of the Cold War with reference to the following :
(i) The Potsdam conference. [4]
(ii) The formation of NATO. [4]
(b) Give an account of. the crisis in east-west
relations in the context of:
(i) The Berlin Wall incident. [4]
(ii) The Cuban missile crisis. [4]
Answer:
(a) The Potsdam Conference : After the surrender of Germany, a conference was held at Potsdam, in Germany by the Allied powers Britain, Soviet Union and the U.S. The main subject of discussion at Potsdam was Germany. At this conference, an agreement was reached on banning fascist organizations, destruction of military power of Germany, reorganization and division’of Germany into four occupation zones. The council of foreign ministers set up at Potsdam Conference signed treaties with Italy, Romania, Bulgaria, Hungary and Finland but no agreement could be arrived at on the question of Germany and Japan. The disagreement over Poland and the differences over Germany became a major source of conflict between the West bloc and Soviet Union.

Formation of NATO : The war war brought to an end on 10th August without Russian Help.

  1. The NATO was formed in April 1949.
  2. The Berlin Blockade exposed the military unreadiness of the West and compelled them to make definite preparations.
  3. In March 1948 Britain, France, Holland, Belgium and Luxembourg had signed the Brussels Defence Treaty promising military help in the case of war.
  4. Now they were joined by the USA, Canada, Portugal, Denmark, Eire, Italy and Norway. They signed the North Atlantic Treaty.
  5. They regarded an attack on one of them as an attack on all of them, and.
  6. Placing their defence forces under a joint NATO command organisation which would coordinate the defence of the west.
  7. The Americans had abandoned their policy of ‘no entangling alliances’ and pledged themselves in advance to military action.
  8. To stop the spread of communism.

(b) The Berlin Wall incident : The Cold War resulted in the separation of Germany into the Western occupied zone and Soviet occupied zone. The German capital, Berlin, was also split into four sectors. It was agreed that Germany and Berlin would eventually be reconstituted and made into a single self- governing nation. But because of the growing mistrust between Western Allies and the Soviet Union, this was prevented from happening. Finally, in 1948, relations broke down completely when the Western Allies announced currency reforms in their section of Germany.

This was in violation of a previous agreement that Germany was to be treated as a single economic unit. The Soviets perceived this as a Western attempt to end the communist regime in Germany. They responded by announcing their own currency reforms and a blockade of all land traffic from West Germany to Berlin to starve out Western interests. The Berlin Wall was erected in 1967 by East Germany’s Communist authorities to prevent mass immigration from East Germany to West Berlin. This wall completely cut off West Berlin from surrounding East Germany by land.

The West responded to this blockade by beginning a massive airlift to West Berlin to bring food, water and necessary supplies to the stranded and isolated inhabitants. Twenty-four hours a day, thousands tonnes of supplies were flown into West Berlin.

The Cuban Missile Crisis : One of the most serious crises in the history of the post Second World War period occurred on the installation of nuclear missile by Soviet Union in Cuba in 1962. Cuba, a communist country, is located in the Latin America, which the U.S. considers its backyard. Fidel Castro, the new ruler of Cuba, nationalized all American-owned estates and factories. As a result, her relations with America worsened whereas relations with Russia improved. The United States severed diplomatic relations with Cuba. Within a few months the U.S. organised the infiltration of 2000 Cuban exiles at the Bay of Pigs in Cuba with the aim of overthrowing the communist government of Cuba.

The invasion was a fiasco and was condemned by the whole world. Russia, apparently at the request of Cuba decided to set up nuclear missile launchers in Cuba which were very close to the American coast. These missiles could be directed to any target thousands of kilometers away, without any operation. Before that, the United States had already set up missile bases near the territory of the Soviet Union and itself remained safe.

In 1962, the United States found through its spy network that the Soviet Union was building missile sites in Cuba. The installation would have brought American territory within easy range of attack. On 22nd October, 1962, the then United States President, John F. Kennedy, announced a blockade around Cuba. The U.S. also prepared to launch an attack on the missile sites in Cuba. This incident could have led to a major world crisis and to nuclear disaster. However, the crisis ended on 26 October, as Khrushchev, the Soviet Prime Minister, sent a message to the President Kennedy that the Soviet Union would remove her missiles from Cuba if the United States pledged not to attack Cuba and withdraw her missiles from Turkey near tlje Soviet Union. The United States agreed to these terms and the crisis was averted.

Question 11.
(a) What were the causes and results of the Arab- Israel Six Day War. of 1967 ? [8]
(b) What were the results of the Yom Kippur War (1973) ? [4]
(c) Why did the Egyptians and Israelis agree to start negotiations in 1978 to resolve their differences ? What part did President Carter of the US play in this peace process ? [4]
Answer:
(a) Causes and results of the Six Day War (1967)

  1. In Iraq a new government came to power which was influenced by the ideas of the Ba’ath party (resurrection)-they believed in Arab independence and unity and were left wing in outlook, wanting social reform and better treatment for ordinary people
  2. In Syria political upheavals brought the Ba’ath party to power.
  3. It supported El Fatah, the Palestinian Liberation Movement(guerrilla force)
  4. The Syrians began to bombard Jewish settlements
  5. In Egypt Colonel Nasser was immensely popular because of his leadership of the Arab world.
  6. Nasser tried to improve the conditions in Egypt- industrialised the country, built factories, Aswan Dam project etc.
  7. Nasser thought the time to be ripe for another attack on Israel
  8. The Russians encouraged Egypt and Syria and kept up a flow of anti-Israeli propaganda.
  9. Syria, Jordan and Lebanon also massed troops along their frontiers with Israel – contingents -Iraq, Saudi Arabia and Algeria

Results :

  1. They launched a series of devastating air strikes which destroyed most of the Egyptian air force.
  2. Israeli troops captured the Gaza Strip and the whole of Sinai from Egypt, the rest of Jerusalem and the West Bank from Jordan and the Golan Heights from Syria.
  3. The Arabs had to accept a UN ceasefire order.
  4. Reasons for spectacular Israeli success: the slow and ponderous Arab troop build-up gave plenty of warnings to them, Israeli superiority in air and inadequate Arab preparations and communications
  5. It was a great success for the Israelis.
  6. Ignored the UN order to return the captured territory.
  7. It acted as a series of buffer zones between Israeli and the Arab states.
  8. New problem- a million of Arabs found themselves under Israeli rule who were living in the refugee camps.
  9. It was a humiliation for the Arab states particularly for Nasser who realized that the Arabs needed outside help in order to free Palestine.

(b) Results of the Yom Kippur War

  1. The end of the war brought a glimmer of hope for some sort of permanent peace.
  2. Egyptian and Israeli leaders came together (though not in the same room) in Geneva.
  3. The Israelis agreed to move their troops back from the Suez Canal enabling the Egyptians to clear and open the canals in 1975.
  4. Arab oil producing states tried to bring pressure to bear on the USA and on Western European states.
  5. This caused serious oil shortages especially in Europe.
  6. The Organisation of Petroleum Exporting Countries (OPEC) began to raise oil supplies Substantially and resulted in inflation and caused an energy crisis in the world’s industrial nations.

(c) 1. The two sides were willing to negotiate as President Sadat was convinced that the Israelis could not be destroyed by force and it was foolish to waste Egypt’s resources in fruitless wars.

2. Israelis were suffering from severe economic problems because of huge defense expenditure and world recession.

3. The USA was pressing the Israelis to settle their differences with some of the Arabs. President Jimmy Carter of USA acted as the Mediator and played a vital role in setting up negotiations between the two sides.

ISC Class 12 History Previous Year Question Papers

ISC History Question Paper 2015 Solved for Class 12

ISC History Previous Year Question Paper 2015 Solved for Class 12

Maximum Marks: 80
Time allowed: Three hours

  • Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.
  • Answer Question 1 (Compulsory) from Part I and five questions from Part II, choosing two questions from Section A, two
  • questions from Section B and one question from either Section A or Section B.
  • The intended marks for questions or parts of questions are given in brackets [ ].

Part—I
Answer all questions

Question 1. [20]
(i) Name one well-known revolutionary organization established in Bengal, in the early years of the twentieth century.
(ii) How did the British Government implement the policy of Divide and Rule in the Morley- Minto Reforms of 1909 ?
(iii) What was Sir Sayyid Ahmad Khan’s main objective in establishing the Mohammedan Anglo-Oriental College ?
(iv) Why did Gandhiji form the Satyagraha Sabha in February, 1919 ?
(v) What was the main objective of the Nehru Report ?
(vi) Why was the All India States People’s Conference formed ?
(vii) What was the most important feature of the Government of India Act of 1935 ?
(viii) Why did the Congress Ministries resign in 1939 ?
(ix) What was the primary objective of Direct Action Day launched by the Muslim League ?
(x) Which international movement was based on the principles of Panchsheel ?
(xi) Why did Mussolini introduce the ‘Battle of Wheat’ programme ?
(vi) Backlash : Politically, the intervention in Suez was a disaster. US President Dwight Eisenhower was incensed. World opinion, especially that of the United States, together with the threat of Soviet intervention, forced
(xii) Mention the significance of the Enabling Law (March 1933).
(xiii) Mention any one adverse effect of the Great Depression (1929) on the Japanese economy.
(xiv) Name the original signatories of the Anti- Comintern Pact (1936).
(xv) Give any one reason for the launch of ‘Operation Overlord’ 1944, by the Allied Powers ?
(xvi) What is the economic extension of the Truman Doctrine known as ?
(xvii) What was the objective of the Berlin Blockade (1948-49) ?
(xviii) Name any two founder members of ASEAN.
(xix) What important result did the Korean War have on the future powers of the UN General Assembly ?
(xx) Why did Nasser nationalize the Suez Canal ?
Answer 1.
(i) The most important feature of the Government of India Act of 1935 was that it provided for provincial autonomy of British India with some restrictions.

(ii) The Congress Ministries resigned in 1939 because at the outbreak of the World War II, the Viceroy proclaimed India’s involvement in the war without prior consultations with the main political parties. When Congress demanded an immediate transfer of power in return for cooperation of the war efforts, the British Government refused. As a result, Congress resigned from power.

(iii) The primary objective of the Direct Action Day was to protest the rejection of the proposed Muslim-majority Pakistan and assert its demand for a separate Muslim homeland.

(iv) The ‘Non-Alignment movement’ was based on the principles of Panchsheel.

(v) On March 23, 1933, the newly elected members of the German Parliament (the Reichstag) met in the Kroll Opera House in Berlin to consider passing Hitler’s Enabling Act. It was officially called the ‘Law for Removing the Distress of the People and the Reich.’ If passed, it would effectively mean the end of democracy in Germany and establish the legal dictatorship of Adolf Hitler.

(vi) The Great Depression affected Japan in many ways. One adverse effect of it on the Japanese economy was that it shrank by 8% during 1929-1931. In both, the cities and the countryside, everyone faced hard times, producing notable increases in strikes and rent disputes. 35,000 employees of a cotton-spinning company went on strike.

(vii) Germany, Italy and Japan were the three power signatories of the ‘Anti-Comintern Pact.

(viii) ‘Operation Overlord’ which was launched by the Allied invasion of North-West Europe in June 1944, was a remarkable achievement. It provided the springboard from which forces from Britain, the United States, Canada, Poland and France could liberate western Europe from German occupation-before advancing on Berlin to defeat Hitler.

(ix) The economic extension of the Truman Doctrine came to be known as the Marshall Aid Plan.

(x) The Berlin Blockade had two objectives :

  1. To prevent the creation of a West German state.
  2. Western powers to be forced to withdraw from Berlin.

(xi) The Korean War, from 1950 to 1953, was the most severe test the United Nations had to face since its inception in 1945. As a part of the whole Cold War scenario, the Korean war was a complicated issue with which the United Nations had to successfully deal with or lose credibility just five years after it had come into being. United Nations Security Council Resolution 82, was a measure adopted by the United Nations Security Council (UNSC) on June 25,1950. The resolution demanded that North Korea should immediately end its invasion of South Korea, the catalyst for the beginning of the Korean War. The measure was adopted by a vote of nine supports, none opposed, and one abstention.

(xii) The Suez Canal, which connects the Mediterranean and Red Seas across Egypt, was completed by French engineers in 1869. For the next 87 years, it remained largely under British and French control, and Europe depended on it, as an inexpensive shipping route for oil from the Middle-east. After World War II, Egypt pressed for evacuation of British troops from the Suez Canal Zone, and in July 1956 President Nasser nationalized the canal, hoping to charge tolls that would pay for construction of a massive dam on the Nile River.

Part-II

Section—A

Question 2.
Radical nationalism took place in the closing years of the 19th century and in the early years of the 20th century. In this context discuss :
(a) The economic and political causes that led to the growth of this phase of the National Movement. [8]
(b) The impact of international events. [4]
(c) The methods adopted by the radical nationalists to achieve their objectives. [4]

Question 3.
(a) Discuss the following factors and events that led to the establishment of the Muslim League (1906): [6]
(i) Economic backwardness of the country.
(ii) The Hindi-Urdu controversy.
(b) What were the principal demands of the Shimla Deputation ? [4]
(c) State any two objectives of the Muslim League. How did the British Government respond to its formation ? [6]

Question 4.
(a) Why was the Simon Commission sent to India in 1927 ? How did the Indians react to it ? [6]
(b) Give an account of the significant development in the National Movement from the Lahore Session of the Congress in 1929 to the suspension of the Civil Disobedience Movement in 1931. [10]

Question 5.
(a) What historic announcement did the British Prime Minister Clement Atlee make on 20th February, 1947 ? [2]
(b) Enumerate the main provisions of the Indian Independence Act. [8]
(c) Why did the Congress accept partition ? [6]
Answer:
(a) The Prime Minister of Britain Clement Atlee, declared on February 20,1947, in the House of Commons that the British would quit India after transferring power to the responsible hands, not later than June, 1948. The idea was that the Indians should settle their issues before that. He also announced the appointment of Lord Mountbatten as Viceroy in place of Lord Wavell.

(b) The main provisions of the Indian Independence Act of 1947, were as follows :

  • On 15th August 1947, after the partition of India, two independent kingdoms, India and Pakistan would be established.
  • Eastern Bengal, Western Punjab, Sindh and North-West Frontier Province would be included in Pakistan.
  • It was not obligatory on the part of both the nations to accept the membership of the British Commonwealth of Nations. The choice was left to India and Pakistan.
  • The title Kaiser-i-Hind, awarded to the British Crown would be abolished and the post of the Secretary of States for India would come to an end.
  • Before the framing of the new Constitutions in India and Pakistan, both the countries would be governed under the Government of India Act, 1953.
  • The native rulers were given the choice to join any State they liked.
  • Those who had joined the civil service before 15th August, 1947 would continue in that service after independence.

They would enjoy the same privileges and rights relating to the remuneration, leave, pension, etc.
Accordingly, Mohammed Ali Jinnah became the Governor General of Pakistan on 15th August, 1947. From the Red Fort in Delhi, Pandit Jawaharlal Nehru delivered his ‘Tryst with Destiny’ speech on 15th August, 1947 as the clock struck 12 and India became independent of the British rule.

(c) The Congress accepted partition under the Mountbatten plan for several reasons :

  • They felt that by accepting the Plan they would get the time to settle in and ensure peaceful and immediate transfer of power.
  • The communal situation of the country was very precarious and accepting the partition was the only way to come out of the situation.
  • The Congress was convinced that if the partition was rejected, the League’s continuous agitation would disrupt the working of the Constituent Assembly.
  • The Congress believed that non-acceptance of the Plan would lead to delay of the transfer of power.

Question 6.
(a) With reference to the conflict between India and Pakistan after the partition, explain the following: [8]

  • The refugee problem.
  • Problems arising from transfer of assets.
  • The causes of the Indus River Waters dispute.
  • The resolution of the Indus River waters dispute.

(b) Why did India follow a policy of Non-alignment under Nehru ? [4]

(c) State the aims of NAM. [4]
Answer:
(a) (i) The Partition of India was the partition of the British Indian Empire which led to the creation, on August 14, 1947 and August 15, 1947, respectively, of the sovereign states of the Dominion of Pakistan and the Union of India . Massive population exchanges occurred between the two newly formed nations in the months immediately following Partition.

This is known as the refugee problem. The division of Punjab and Bengal witnessed the biggest migration ever known in world history. This problem may be divided into three heads:

  1. The incoming refugees from West Punjab (New in Pakistan) to East Punjab.
  2. The refugees from North-West Frontier Province.
  3. The refugees from the Province of Sind and,
  4. The refugees from East Bengal to West Bengal.

According to the report of the Government of India, between September 1947 and March 1948, a little more than one million people crossed once from the new state of Pakistan to East Punjab on foot, over one and a half million by rail, 364 thousand by motor transport and 28 thousand by air. The rehabilitation of millions of people was a Herculean task. The main migration in Punjab in both directions took place for four months. The properties of the refugees were destroyed by communal riots. People had to live in camps.

The problem of division of assets of India, between Pakistan and India kept Indo-Pak relations tensed and strained during the initial years of their relations. On 14th August 1947, the cash balance of India was about 4,000 millions out of which Pakistan wanted 1,000. A dispute arose which was referred to as Arbitrate Tribunal which decided that 750 millions should be paid to Pakistan as its share. India implemented the agreement. Another problem was Pakistan refusing to pay 55 crores which it was to pay as its share of foreign debt. There was the problem of division of military stores and delinking of Banking services created tension between the two nations.

The partition of British India created a conflict over the plentiful water of the Indus basin. The newly formed states were at odds over how to share and manage what was essentially a cohesive and unitary network of irrigation. Furthermore, the geography of partition was such that the source rivers of the Indus basin were in India. Pakistan felt its livelihood threatened, by the prospect of Indian control over the tributaries that fed water into the Pakistani portion of the basin. Pakistan felt acutely threatened by a conflict over the main source of water for its cultivable land. During the first years of partition, the water of the Indus was apportioned by the Inter-Dominion Accord of May 4, 1948.

This accord required India to release sufficient water to the Pakistani regions of the basin in return for annual payments from the government of Pakistan. The accord was meant to meet immediate requirements and was followed by negotiations for a more permanent solution. Neither side, however, was willing to compromise their respective positions. From the Indian point of view, there was nothing that Pakistan could do to prevent India from any of the schemes to divert the flow of water in the rivers. Pakistan’s position was dismal and India could do whatever it wanted. Pakistan wanted to take the matter to the International Court of Justice but India refused, arguing that the conflict required a bilateral resolution.

The water dispute between India and Pakistan was settled through the intervention of Eugene Black, the President of the World Bank.
The scheme of the World Bank was as follows :

  1. The total water of Indus and its tributaries was divided in the proportion of 80:20 ratios.
  2. India agreed to allow the flow of Indus, Jhelum and Chenab all time. The irrigated areas of India would continue to receive waters from these rivers.
  3. India would be able to store a total of 2.85 million acres feet of water for various purposes from the tributaries of these Western rivers namely, Indus, Chenab and Jhelum.
  4. The agreement would be made for a period of ten years. During this time Pakistan would construct canals to replace supplies hitherto received from Eastern rivers viz. Ravi, Sutlej andBeas.
  5. India agreed to make a fixed contribution of ? 83.3 crores for the construction work of those canals by Pakistan.
  6. India would pay this amount in ten equal annual instalments to the World Bank.
  7. Austria, Canada, Germany, Britain, New Zealand and America agreed to pay generously to this Indus Basin Development Fund. Pakistan would receive ? 333.3 crores for construction of irrigation reservoirs and link canals.
  8. A permanent Indus Commission would be formed. This Commission would be responsible for implementing the terms of the treaty. If any dispute could not be resolved by negotiation, the matter would be referred to a neutral expert or to the Court of Arbitration for final decision.

But Indian public opinion was not happy because India got a small share of river waters. India would also pay huge amount to Pakistan for construction of link canals. Jawaharlal Nehru went to Karachi and signed the Indus Water Treaty on 19th September, 1960. Nehru hailed 19th September as a ‘memorable day’. Thus, India was able to settle water problem with her new neighbour Pakistan.

(b) The Indian foreign policy in the yearly years after independence was ‘neutral’ because India wanted to maintain safe distance from the two power Blocs the Western and Soviet Bloc. The two camps led by the United States and the Soviet Russia wanted to extend their influence all over the world. India followed a policy not to be influenced by these two power Blocs. Thus, the Non-Alignment Movement (NAM) was largely a product of India’s efforts to organize a collective answer to ‘Bloc’ politics of the great powers and also to develop friendly relations among the countries who were trying to free themselves from colonial dominations. Another aim was to promote peace in the world.

It was important for the countries of Africa and Asia to receive the support of the power blossom well to grow economically. A peaceful friendly environment could only facilitate this outcome. The 1950s were the Cold war era. The NATO had already been set up and military alliances were forming in Asia. In this situation India proclaimed a policy of Panchsheel.

(c) (i) To maintain international peace.
(ii) To abolish imperialism and colonialism and laying stress on self-determi-nation, equality and freedom.
(iii) To maintain mutual respect for each other’s territorial integrity and sovereignty.
(iv) Maintaining mutual non-aggression.
(v) Mutual non-interference in each other’s affairs.
(vi) Equality and mutual benefit.
(vii) Peaceful co-existence.

Section—B

Question 7.
(a) Give a brief account of the circumstances of the backstage deal that enabled Hitler to come to power legally in 1933. [4]
(b) Discuss the changes brought about by Hitler in the following spheres of life of the people of Germany: [8]
(i) Educational
(ii) Cultural
(c) What extreme measures did Hitler adopt against the Jews ? [4]

Question 8.
Aggressive nationalism in Italy and Germany eventually led to the outbreak of the Second World War. In this context, discuss the following :
(a) Italy’s invasion of Abyssinia (1935). [6]
(b) Introduction of conscription by Hitler. [4]
(c) Germany’s Anschluss with Austria (1938). [6]
Answer:
(a) In 1935, taking as an excuse of a certain boundary dispute with neighboring Italian colonies, Italy invaded Abyssinia. The League of Nations failed to stop Italian aggression. It invited its members to impose sanctions upon Italy but the league members refused. Abyssinia was practically abandoned and Italy with-drew from the League of Nations. Mussolini ignored the League, and invaded Abyssinia. The Abyssinian Emperor, Haile Selassie, went to the League to appeal for help, but it did nothing. In fact, Britain and France secretly agreed to give Abyssinia to Italy (the Hoare-Laval Pact). The invasion was a war for both sides and proved the ineffectiveness of the League of Nations, as it condemned Italy’s actions and attempted to impose universal sanctions on Italy but failed.

(b) Following President Paulvon Hindenburg’s death on August 2, 1934, Adolf Hitler became the commander-in-chief of Germany. All of the officers and soldiers for Germany’s military were required to pledge their loyalty to the new Fuehrer. After he assumed power, Germany started to openly disregard most of the military restrictions, established by the Treaty of Versailles, and reinstated conscription on March 16,1935.

The new conscription law was introduced with the name of ‘Wehrmacht.’ Therefore, March 16, 1935, is regarded as the Wehrmacht’s founding date. The official announcement of the Wehrmacht existence was announced on October 15,1935.

Even though the scale of Germany’s standing army was required to be around 1,00,000 men, new groups of conscripts that were almost equal to that size started to receive military training every year after 1935. The authority and the organization of the Wehrmacht is viewed by many to be Nazi creations, in spite of the various political affiliations of the high command. The Wehrmacht’s insignia was based on the famous Iron Cross, which had been widely used for tank and aircraft marking during the latter part of the First World War. Nazi revanchism and expansionism led to World War II, which resulted in the destruction of Germany’s political and economic infrastructures and led to its division.

(c) The Anschluss was the annexation of A ia by Nazi. Germany in March, 1938. The popularity of the Austrian Nazi party grew in Austria as Hitler gained power in Germany. There was a demand by the Austrian Nazis of Austria to join Germany. In 1935 Austrian chancellor, Kurt von Schuschnigg, used the police to suppress the Nazi supporters in Austria. Following the increasing violence and demands from Hitler, Austria agreed to a union. Schuschnigg met with Hitler on February 12, 1938, at Berchtesgaden in an attempt to avoid the take over of Austria.

Hitler presented Schuschnigg with a set of demands which included appointment of the known Austrian Nazi sympathizers, to be positioned at great power in the Austrian government. In return Hitler would reaffirm his support for Austria’s national sovereignty. Schuschnigg accepted Hitler’s terms. On 9 March, 1938, in an effort to preserve Austria’s independence, Schuschnigg scheduled a plebiscite on the issue of unification for 13th March. Hitler sent an ultimatum to Schuschnigg on 11th March, demanding that he should hand over all power to the Austrian Nazis or face an invasion. Schuschnigg resigned and allowed the Nazis to take over the government. On 12th March, Germany invaded, and the enthusiasm that followed gave Hitler the cover to annex Austria outright on 13 th March.

Question 9.
In the context of the Second World War, discuss the following :
(a) Hitler’s final miscalculation over Poland. [4]
(b) The causes and consequences of the German invasion of Russia (1941). [6]
(c) Any three reasons for the defeat of the Axis Powers in the Second World War. [6]
Answer:
(a) Hitler’s arrogance and his belief that he could use tyrannical force over the sovereignty of other European states, resulted in a severe miscalculation that made Germany enter a war, that it did not want. Strategically speaking, Germany needed to stay out of a big war that was going to last a long time. Hitler miscalculated and got Germany into such a war. First, Hitler did not believe that the Allies would actually go to war over Poland. He was wrong about that,’obviously. That was a major strategic blunder. Second, Hitler believed that the British would make peace with him once he had control over Western Europe. He was, once again, wrong. The outbreak of a general European war in September 1939, had its immediate origin in the illusions and miscalculations over the Polish crisis.

(b) Hitler attacked Russia in 1941, to rescue supplies of food and oil from the Russian territories of Ukraine and the Caucasus.
According to Hitler, a war against Russia would acquire Lebensraum (“living space”) in Eastern Europe to ensure the survival of Germany for generations to come. It would relieve acute labour shortage and all these would combine to leave Germany in an unassailable global position of power.
The consequences of the war was :

  1. The operation blundered because the blitzkrieg was not fast enough.
  2. The kind of force the Soviet Union could pull together was underestimated.
  3. An underestimation of the cold winter

(c) There were a number of reasons for the defeat of the Axis Power in the Second World War :
The German army was regarded as invincible at the initial stage of the war, but the myth gradually came to an end. At first, the Allied Powers could not understand how to cope with the German Blitzkrieg. But very soon they realized from their early failures how to tackle this problem. The Allied Powers under-stood the importance of air support and air carriers. With superior air and naval power, they won the battles of Atlantic and the Pacific.

The basic weakness of the Axis Powers was their shortage of rubber, cotton, nickel and, after mid-1994, oil. To win the war, constant supply of raw materials were urgently needed and in this point, the Axis Powers were very much handicapped.

It was very difficult for the Axis Powers to contest with the combined resources of the USA, USSR and the British Empire. In Germany’s case, Mussolini was partly a burden because of his incompetence. This became a constant drain on Hitler’s resources. On the other side, the Soviet Russia reconstructed their industries and continued production to a large extent. It has been estimated that by 1944 Russia had four times as many tanks as the Germans and could put twice as many men in the field. America manufactured over 70,000 tanks and 1,20,000 air crafts a year with which the Germans and the Japanese could not compete at all.

Question 10.
The period after the Second World War was marked by tension and cooperation. Answer the questions below, with reference to this statement :
(a) Why was there a thaw in the Cold War in the 1950s ? Give examples to show that the thaw was only partial. [6]
(b) What led to a permanent relaxation of tensions (detente) in the 1970s ? [4]
(c) Why did many European world leaders promote the idea of greater economic cooperation and unity in Western Europe after the Second World War ? [6]
Answer:
(a) The death of Stalin in March, 1953, was probably the starting thaw because new leaders now came into the forefront. The thaw showed itself in several ways. The signs were shown when Korean War came to an end by a peace treaty and the end of the war in Indo china. The Russians also made important concessions in 1955 when they agreed to wind up their military base in Finland. Russian leader, Bulgarian attended a summit meeting in Geneva where he met the American President Elisenhower. Then, Russia lifted her veto power on the admission of sixteen new members to the United Nations. Khrushchev paid a visit to Tito and thus, quarrel with Yogoslavia was healed to some extent. The Come in form’ was abandoned, suggesting more freedom for the satellite states.

The signing of the Austrian State Treaty on May 1955 was another step forward for thaw. After the Second World War, Austria was divided into four zones of occupation with the capital Vienna in Russian zone. Austria was allowed her own government because she was vied not as a defeated enemy but as a state liberated from the Nazis. Three Western occupying powers organized the recovery of their respective zones but Russia collected reparation in the form of food supply. Early in 1955, the Austrian Government persuaded the Russian Government to be more cooperative. Russia had an apprehension of a merger between West Germany and western Austria.

The Russian Government became cooperative and signed an agreement. As a result, all occupying troops were withdrawn and Austria became independent. But Austria was not to be united with Germany, her armed forces were restricted and she was to remain neutral in any dispute between Western and Eastern Bloc. This meant that Austria could join neither the NATO nor the European Economic Community. The Austrians were not happy for the loss of German-speaking people of South Tyrol which were given to Italy.

In fact, the thaw was only partial. Khrushchev sometimes followed conciliatory policy and sometimes a policy seemed to be a threat to the Western Bloc. He did not show any desire to relax Russian control over the satellite states. When the Hungarians revolted in Budapest against the Communist Government, the movement was crushed by Russian tanks in November 1956.

Khrushchev now signed the Warsaw Pact in 1955 with the satellite states just after Western Germany as admitted to the NATO. The Pact was a mutual defense agreement with the satellite states. Apart from this, to put the Western Bloc on pressure, Russia successfully tested in inter continental ballistic missile and launched first space satellite ‘ Sputnik-1’.

(b) Detente was a permanent relaxation in international affairs during the Cold War rather than just a temporary relaxation (the so-called “thaw”). Detente is a term usually associated with the relations between America, Russia and China. The reasons for the detente were :

  • The horrors of Vietnam shocked people.
  • There was a growing fear of a nuclear holocaust.
  • China – she was fearful of her isolation in the world. China was also worried by her worsening relations with USSR.
  • USA – she realized that war meant the massive cost of weapons production and maintaining a huge armed force. A peaceful relationship with the USSR would be very beneficial to USA especially after the cost of the Vietnam War.

USSR – USSR was spending a huge amount on weapons at the expense of basic household goods. Living standards were poor and USSR was also aware that her relationship with China was far from good while USA was trying to improve hers with China. To make the event a permanent one, USSR and USA established in 1963 a – hot-line after Cuban Missile Crisis; both agreed to only use underground tests for nuclear explosions; in 1969 the Strategic Arms Limitation Talks (SALT) started; in 1972 Richard Nixon, USA president, visited Moscow; in 1973-Leonid Brezhnev, USSR leader, visited Washington 1974-Nixon visited Moscow. In 1971, a move was made to improve relationships when China invited an American table tennis team to China. Hence, the term “Ping-pong” diplomacy. USA’s response was to support China’s entry into the U.N.

(c) The Second World War had brought colossal destruction to Europe. Every participating country was economically exhausted after the war.
During the Second World War, many political leaders of the western European countries had seen the destructive effects of national self-interest. They advocated more economic and political co-operation among the European states so as to avoid wars in the future.

After the Second World War, it was widely believed that European economic recovery could be quickened by a co-operative effort among the European states. There was also a growing conviction that in the modem competitive world, the small nation-states could not be economically viable.

In 1948, the European economy began to revive. From 1950 on wards, European economic growth became rapid. There are a number of factors which can explain the rapid economic recovery of Europe :
The small European states could compete with the two economic giants, Russia and the United States, only through the removal of tariff barriers between themselves, economic co-operation and the utilization of their economic resources on a continental scale.

Economic recovery was helped by the changes in Government policies. Before the war, most European Governments adopted the laissez-faire policy. After the Second World War, most of them tried to stimulate the economic growth of their own countries by more Government investments. In Britain, the Beveridge Report was adopted and it meant that the British Government would make heavy investment in developing the welfare services in Britain.

Growth in world trade also helped economic recovery. After the war, many European countries had realized the disastrous effects of tariffs on inter-European trade. Trade between Europe and the developing countries in Asia and Africa also increased after the war.

Scientific and technological advances after 1945 also helped economic recovery. Both chemical and electrical engineering industries made rapid advances during and after the war. The demand for these new products ensured continuing prosperity in the post-war years.

The most important factor in assisting speedy economic recovery in the immediate post-war years was the injection of foreign aid into the European economy.

Question 11.
With reference to the conflict in the Middle- east, answer the following questions:
(a) Give a brief account of the Arab-lsrael conflict in Palestine after the First World War and explain how it led to the outbreak of war in 1948. [8]
(b) State the results of the Arab-lsrael war (1948-49). [4]
(c) What were the main points agreed upon in the Camp David Peace Accord (1979) ? [4]

Answer 11.
(a) With the outbreak of World War I, the British Government decided to drive away the Turks from Arabia and the Middle-east. The Ottoman Sultan was an ally of Germany. The British agents contacted the Grand Sheriff King Hussain of Mecca to give a call to the faithful Muslims to wage a Jihad against the Turks. The British Government promised king Hussain independent Arabia after the end of the war. Consequently, the Arabs joined the British against the Turks.

Though pan Arab nationalism swept the Arab World but Hussain failed to get what he and his people wished. On the other hand as the Jews were persecuted by the Christians in Europe, they were determined to protect their nationalism and regain their lost homeland in Palestine. With the outbreak of the First World War, the British Government faced severe economic crisis and approached great Jewish bankers for loan and subsidy. Under pressure from the Jewish Congress, in return for this loan, Lord Balfour made a public declaration in the Parliament, “His Majesty’s Government views with favour the establishment in Palestine of a national home for the Jewish people and will use their best endeavor to facilitate the object.” The Balfour Declaration of 1917 was highly contradictory to the Hussain-Macmohan correspondence. This mutually contradictory diplomacy of the British lay at the root of the Palestine problem.

After the First World War, Arab territories were mostly divided between Britain and France as mandated territories under the nominal authority of the League of Nations. Palestine became a British mandate. Its administration fell upon Britain.

When the question of conflicting pledges was raised at the League of Nations, Britain cleverly pointed out that there was really no duplicity and conflict. If they promised Arabia to Hussain, Palestine was certainly not included in the pledge. The name of Palestine was not mentioned in the Hussain-Macmohan letters. If a homeland was assured to the Jews, it meant a part, not the whole of Palestine.

Due to the Arab-Jewish rift, the British Government began to seek ways and means to solve the Palestine problem. In 1936, a Royal Commission under Peel was appointed in Palestine, which reported that Palestine should be partitioned into two small Jewish states-the holy places were to be kept under British mandate and the rest was to be annexed to Jordan. This proposal was out rightly rejected by the Arab leaders and partly rejected by the Jews. Meanwhile, the Second World War broke out.

The clever Zionist leaders became aware that America had emerged as a centre of world politics after the war. They shifted the headquarters of the Zionist movement from London to New York. Five million Jewish Americans supported the claim for a Jewish homeland and no American politician could ignore 5 million votes. So, both the Democrat and Republican parties became sympathetic to the Jewish cause. In a Zionist Congress at New York, the Jews demanded :

  1. Declaration of a Jewish state in Palestine.
  2. Formation of a Jewish voluntary force.
  3. Free, unfettered entry of Jews in Palestine

After the New York Zionist Conference, Britain informed the U.N.O. that she would withdraw her troops and officials from Palestine by 1948. To resolve this problem, an Anglo-American Commission was appointed. Its recommendations were rejected by both the Arabs and the Jews. At this point, the Jewish terrorism was intensified. On Nov. 19, 1947, the U.N.O. decided to partition Palestine on the lines laid down by the Royal Commission, the Zionist leaders accepted the proposal but the Arabs rejected it. The U.N.O. sent a commission to fix the boundary of the new Jewish state. On Aug. 1, 1948, the Zionists declared the birth of the state of Israel on the lines laid by the U.N. Commission with Dr. Chain Wise men as the President and David Ben Gurion as the Prime Minister.

The United States granted recognition to the new state within a day and the Soviet Union followed it. Britain and other countries did not delay in granting recognition. Thus, the state of Israel was bom with violence and the Arab-Israeli conflict continues from 1948 to the present date.

(b) The mean events of Arab-Israel war spread ‘ over a period from 1948-73. During the post- Second World War period, no other question was so tough, chronic and violent as the Arab- Israel question. The Arabs under Nasser, the President of Egypt, would not hear any term except eradication of the Jews from Palestine. The Israelis gave up conciliation policy. By their superior strategy and skill, they tried to crush the Arabs to dust. As soon as the state of Israel was declared, Egypt, Syria and Jordan attacked it.

The Israeli General Valerian routed the enemies on all sides by small, tidy, very well equipped forces of Israel. Israel very soon captured west of the Gaza strip and west bank of river Jordan and evicted one million Arabs from the occupied zone. They came to be known as Palestinian refugees. Their cries for homeland were organized by Yasser Arafat and this added new knots to the already existed problem of Palestine. The UNr- declared cease fire but Nasser declared a state of war with Israel ignoring the UN mandate.

(c) Camp David Accords, agreements between Israel and Egypt signed on September 17, 1978 that led in the following year to a peace treaty between those two countries, the first such treaty between Israel and any of its Arab neighbors. Brokered by U.S. President Jimmy Carter between Israeli Prime Minister Menachem Begin and Egyptian President Anwar el-Sadat and officially titled the “Framework for Peace in the Middle-east,” U.S. presidential retreat at Camp David, Maryland. Sadat and Begin were awarded the Nobel Prize for Peace in 1978 for their contributions to the agreements.

The eventual outcome of these “Framework for Peace in the Middle-east,” had three parts :

  1. a process for Palestinian self-government in the West Bank and Gaza,
  2. a framework for the conclusion of a peace treaty between Egypt and Israel, and
  3. a similar framework for peace treaties between Israel and its other neighbors. The Prime Minister and the Israeli

Knesset agreed that a transitional self-governing Palestinian authority was to be elected to replace Israeli political and military forces in the occupied territories.

ISC Class 12 History Previous Year Question Papers

ISC Physics Question Paper 2012 Solved for Class 12

ISC  Physics Previous Year Question Paper 2012 Solved for Class 12

Maximum Marks: 70
Time allowed: 3 hours

  • Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time
  • Answer all questions in Part I and six questions from Part II, choosing two questions from each of the Sections A, B and C.
  • All working, including rough work, should be done on the same sheet as, and adjacent to, the rest of the answer.
  • The intended marks for questions or parts of questions are given in brackets [ ].
  • Material to be supplied: Log tables including Trigonometric functions
  • A list of useful physical constants is given at the end of this paper.

Part – I
(Answer all questions)

Question 1.
A. Choose the correct alternative A, B, C or D for each of the questions given below : [5]
(i) A body has a positive charge of 8 × 10-19 C. It has :
(A) an excess of 5 electrons
(B) a deficiency of 5 electrons
(C) an excess of 8 electrons
(D) a deficiency of 8 electrons

(ii) Figure below shows five dc sources (cells). Their emfs are shown in the figure.
ISC Physics Question Paper 2012 Solved for Class 12 1
Emf of the battery AB is :
(A) 8 V
(B) 6 V
(C) 4 V
(D) 2 V

(iii) Which one of the following graphs in figure represents variation of reactance ‘Xc’ of a capacitor with frequency ‘f’ of an ac supply :
ISC Physics Question Paper 2012 Solved for Class 12 2
ISC Physics Question Paper 2012 Solved for Class 12 3
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ISC Physics Question Paper 2012 Solved for Class 12 5
(iv) White light is passed through sodium vapors contained in a thin walled glass flask and the transmitted light is examined with the help of a spectrometer. The spectrum so obtained is :
(A) Absorption spectrum
(B) Solar spectrum
(C) Band spectrum
(D) Continuous spectrum

(v) Binding energy of a nucleus is of the order of:
(A) Electron volt (eV)
(B) Kilo electron volt (KeV)
(C) Mega electron volt (MeV)
(D) a joule (J)

B. Answer all questions briefly and to the point: [15]
(i) A point charge of 5 × 10-6 C experiences a force of 2 × 10-3 N when kept in a uniform electric field of intensity E. Find E.

(ii) Which conservation principle is involved in Kirchhoff’s first law of electric circuits ?

(iii) Write an expression of magnetic flux density ‘B’ at a point in end – on position or an axial position of a magnetic dipole. (Derivation not required.)

(iv) In a moving coil galvanometer, what is meant by a radial magnetic field ?

(v) Variation of alternating current T with time lt’ is shown in the graph below:
ISC Physics Question Paper 2012 Solved for Class 12 6
What is the rms value of this current ?

(vi) Which electromagnetic radiation has wavelength greater than that of X rays and smaller than that of visible light ?

(vii) How did Fresnel construct a biprism in order to study interference of light ?

(viii) State Brewster’s law of polarisation of light. ‘

(ix) A thin convex lens (L1) of focal length 80 cm and a thin concave lens (L2) of focal length f are kept co-axially, 20 cm apart as shown in figure below. When a narrow and parallel beam of light is incident on the convex lens, beam emerging from the concave lens is also a parallel beam Find f.
ISC Physics Question Paper 2012 Solved for Class 12 7
(x) What condition must be satisfied by two thin lenses kept in contact so that they form an achromatic doublet, i.e., a combination free from chromatic aberration ?

(xi) Threshold frequency of a certain metal for photoelectric emission is 5 × 1014 Hz. Calculate its work function.

(xii) What conclusion was drawn by Rutherford based on Geiger-Marsden’s experiment on scattering of alpha particles ?

(xiii) Write a balanced nuclear reaction showing emission of a β particle by \(\begin{array}{l}{234 \mathrm{Th}} \\ {90}\end{array}\) (Symbol of daughter nucleus formed in the process is Pa.)

(xiv) What is the essential difference between the working of a nuclear reactor and that of a fission bomb ?

(xv) State one important use of Zener diode.
Answer:
ISC Physics Question Paper 2012 Solved for Class 12 8
(ii) The Kirchhoff’s first law of electric circuit is based upon the principle of conservation of electric charge which implies that at any node (junction) in an electrical circuit, the sum of current moving into that node is equal to the sum of the current flowing out of that node.
\(\sum_{k=1}^{n} I_{k}=0\)

(iii) Expression for the magnetic flux density ‘B ’ at point in or an axial position of a magnetic dipole can be written as
\(\mathrm{B}=\frac{\mu_{0}}{4 \pi} \frac{2 \mathrm{M}}{r^{3}}\) (due to a short dipole)
where M is the moment of magnet, r is the distance of the point from mid-section of magnet.

(iv) In a moving coil galvanometer, the coil is suspended between the concave pole pieces. The magnetic field is thus directed along the radius of the concave pole pieces. This magnetic field is called radial magnetic field. The advantage is that in all positions of the coil, the magnetic field is parallel to plane of the coil.

(v) It is clear from the graph that peak current of ac is given by I0 = 5√2 A
\(\text { Now, } I_{\text {rms }}=\frac{I_{0}}{\sqrt{2}}=\frac{5 \sqrt{2}}{\sqrt{2}}=5 \mathrm{A}\)

(vi) Ultraviolet ray has a wavelength greater than X rays and smaller than that of visible light.

(vii) Biprism was constructed by the combination of two prisms of very small refracting angles, placed base to base. In practice, the prism is made from a single plate by grinding and polishing, so that it is a single prism with one of its angles about 179° and other two about 30° each.

(viii) Brewster’s states that for a given medium of refractive index μ the angle of polarisation is related as μ = tan ip, where ip is angle of polarisation. Then refractive index of a medium is equal to the tangent of the angle of polarisation.

(ix) It is clear from the figure that in the absence of the lens L2, the rays from infinity will come to focus at a distance of 80 cm from the lens L1. The image at serves as a virtual object for the concave lens and final image is formed at ∞.
∴ For the concave lens
ISC Physics Question Paper 2012 Solved for Class 12 9
i.e., the ratio of the dispersive power of the materials of the two lenses is the same as the ratio of their focal length. Further, one lens in the combination must be concave and the two lenses must be of different material.
ISC Physics Question Paper 2012 Solved for Class 12 10
(xii) The following conclusions were drawn by Rutherford from scattering of α-particles :
(1) The whole of +ve charge is concentrated in the nucleus of the atom. This is so because most of a-particles pass straight through the nucleus. Since only a very small fraction of the a-particles is scattered, nucleus must be small.
(2) The whole mass of the atom is also concentrated in a small region.
(3) Nucleus is surrounded by a cloud of electrons whose total – ve charge is equal to the total +ve charge on the nucleus.

(xii) The required nuclear reaction is
\(_{92} \mathrm{U}^{24} \longrightarrow_{93} \mathrm{U}^{234}+_{-1} \beta^{0}+\overline{\mathrm{v}}, \text { where } \overline{\mathrm{v}} \text { is called anti-neutrino. }\)

(xiv) The main difference between the nuclear reactor and a fission bomb is that whereas in a nuclear reaction, the chain reaction can be controlled and energy produced can be used for useful purpose, the chain reaction in fission bomb once started cannot be controlled and causes destruction.

(xv) A zener diode is used as a voltage stabiliser.

Part-II
Answer six questions in this part, choosing two questions from each of the Sections A, B and C.

Section-A
(Answer any two questions)

Question 2.
(a) Three point charges Q1 = 25 μC, Q2 = 50 μC and Q3 = 100 μC, are kept at the comers A, B and C respectively of an equilateral triangle ABC having each side equal to 7.5 m. Calculate the total electrostatic potential energy’ of the system. [4]

(b) Obtain an expression for equivalent capacitance C, when three capacitors having capacitance C1, C2 and C3 are connected in series. [3]

(c) When a potential difference of 3 V is applied between the two ends of a 60 cm long metallic wire, current density in it is found to be 1 x 10-7 Am-2 . Find conductivity of the material of the wire in SI system. [2]
Answer:
ISC Physics Question Paper 2012 Solved for Class 12 11
ISC Physics Question Paper 2012 Solved for Class 12 12
ISC Physics Question Paper 2012 Solved for Class 12 13
ISC Physics Question Paper 2012 Solved for Class 12 14
(b) In the figure are shown, three capacitor of capacity C1, C2 and C3 in series. In this case, the charge Q flowing through each of the capacitors is the same but difference across them is different. Let V be the potential difference of the battery and V1, V2 and V3 be the potential difference across them respectively. Then
ISC Physics Question Paper 2012 Solved for Class 12 15
ISC Physics Question Paper 2012 Solved for Class 12 16
ISC Physics Question Paper 2012 Solved for Class 12 17
Question 3.
(a) In the circuit shown in figure below, E is a battery of emf 6 V and internal resistance 1 Ω. Find the reading of the ammeter A, if it has negligible resistance : [4]
ISC Physics Question Paper 2012 Solved for Class 12 18
(b) With the help of a neatly drawn and labelled diagram, obtain balancing condition of a Wheatstone bridge. [3]

(c) State any two differences between Peltier effect and Joule effect [2]
Answer:
ISC Physics Question Paper 2012 Solved for Class 12 19
ISC Physics Question Paper 2012 Solved for Class 12 20
(b) In the figure is shown an unbalanced Wheatstone bridge. A current Ig flows from D to B i.e., D is at a higher potential. Let VA, VB, VC, and VB be the potential at the points A, B, C, and D respectively, then by applying Ohm’s law, we have
ISC Physics Question Paper 2012 Solved for Class 12 21
ISC Physics Question Paper 2012 Solved for Class 12 22
ISC Physics Question Paper 2012 Solved for Class 12 23
(c) Two differences between Peltier effect and Joule effect are :
ISC Physics Question Paper 2012 Solved for Class 12 24
Question 4.
(a) Figure alongside shows a point P near a long conductor XY carrying a current I. MN is a short current carrying conductor, kept at the point P, parallel to the conductor XY. [2]
(i) What is the direction of magnetic flux density ‘B’ at the point P due to the current flowing through XY ?
(ii) What is the direction of the force experienced by the conductor MN due to the current flowing through XY ?

(b) What are four different types of energy losses in a transformer? State how to reduce/minimize any one of them. [3]

(c) A 50 μF capacitor, a 30 Ω resistor and a 0.7 H inductor are connected in series to an ac supply which generates and emf ‘e’ given by e = 300 sin (200 t) Volt. Calculate peak value of the current flowing through the circuit. [4]
Answer:
(a) (i) By applying the thumb rule, we find that the magnetic field at P is directed downward perpendicular to the conductor MN.
(ii) Since the currents through the conductor MN and XY are flowing in the same direction, the force will be attractive i.e., the conductor MN is attracted towards XY.
ISC Physics Question Paper 2012 Solved for Class 12 25
(b) The four losses in a transformer are :
(i) Joules losses ,
(ii) Loss due to hysteresis
(iii) Eddy current losses
(iv) Loss due to leakage of flux
Eddy current losses in a transformer take place in the core of the transformer. This loss is reduced by laminating the iron core.

(c) We know that impedance Z of the LCR circuit is
ISC Physics Question Paper 2012 Solved for Class 12 26

Section-B
(Answer any two questions)

Question 5.
(a) On the basis of Huygens’s wave theory, prove Snell’s law of refraction of light. Draw a neat and labelled diagram. (Postulates of Huygens’s wave theory not required). [4]

(b) In Young’s double slit experiment using monochromatic light of wavelength 600 nm, interference pattern was obtained on a screen kept 1.5 m away from the plane of the two slits. Calculate the distance between the two slits, if fringe separation/fringe width was found to be 1.0 mm. [2]

(c) Draw a labelled graph to show variation in intensity of diffracted light with angular position, in a single slit diffraction experiment. [2]
Answer:
ISC Physics Question Paper 2012 Solved for Class 12 27
We focus our attention on the instant ray 1 strikes the surface and subsequent time interval. Until ray 2 strikes the surface. During this time interval, the wave at A send out a Huygens’s wavelet towards D. In the same time interval, the wave at B sends out Huygens’s wavelet towards C. Since two wavelets travel through different mediums, thus radii of the two wavelets are different.
ISC Physics Question Paper 2012 Solved for Class 12 28
ISC Physics Question Paper 2012 Solved for Class 12 29
Question 6.
(a) You are provided with a narrow and parallel beam of light. State how you will determine experimentally, whether it is a beam of ordinary (unpolarised) light, partially polarised light or completely polarised light. [3]

(b) For any prism, show that refractive index of its material is given by : [3]
\(n \text { or } \mu=\frac{\sin \left(\frac{A+\delta_{m}}{2}\right)}{\sin \left(\frac{A}{2}\right)}\)
where the terms have their usual meaning.

(c) Figure below shows a parallel beam of monochromatic light incident on a convex spherical surface, radius of curvature R = 30 cm, which separates glass (refractive index = 1.6) from air. Find the position of the image formed due to refraction of light at this single spherical surface.
ISC Physics Question Paper 2012 Solved for Class 12 30
Answer:
(a) Our eyes cannot distinguish between polarized and unpolarised light. Polaroids can, however, be used to examine whether a given light is polarized or unpolarised. For this, the given light is passed through a Polaroid and the Polaroid is rotated about the incident light.
(i) If on rotating the Polaroid through one complete rotation there is no change in the intensity of the emergent light in any position, then the given light is unpolarised.
(ii) It there is change in the intensity of emergent light and in one complete rotation of Polaroid the intensity became twice maximum or twice zero, then the given light is completely plane polarized.
(iii) If the intensity of light changes but never became zero, then the light is partially polarized.

(b) In the figure is shown, a ray light PQ incident at an angle i on the face AB of a prism ABC. This ray is refracted along QR at an angle r1. This refracted ray is incident on the face AC at an angle r2 and emerges along RS at an angle e. Angle of deviation is the angle between the incident ray produced forward and emergent ray produced backwards. Clearly,
ISC Physics Question Paper 2012 Solved for Class 12 31
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ISC Physics Question Paper 2012 Solved for Class 12 34
Question 7.
(a) (i) What is meant by :
(A) Spherical aberration ?
(B) Chromatic aberration ? [3]
(ii) How can spherical aberration be reduced/minimized ? Suggest any one method.

(b) A compound microscope consists of an objective of focal length 2 cm and an eye piece of focal length 5 cm. When an object is kept 2.4 cm from the objective, final image formed is virtual and 25 cm from the eye piece. Determine magnifying power of this compound microscope in this set up i.e., in normal use. [3]

(c) (i) Define Resolving Power of a simple astronomical telescope. [2]
(ii) State one advantage of a reflecting telescope over refracting telescope.
Answer:
(a) (i) (A) Spherical aberration : When a parallel beam of light is incident on a lens, it is observed that the rays suffering refraction from the peripheral portion of the lens comes to focus at a point near the lens and rays suffering refraction from near the axes of the lens comes to focus at a point away from the lens. Due to this, the image is not sharp and is spread along the axis. This defect in the image is called spherical aberration. This aberration is reduced by
(i) using crossed lens
(ii) using an aperture or a stopper.
(B) Chromatic aberration: A lens, as we know, is a combination of prisms placed one above the other with central region behaving as plane glass plate. A prism produces both deviation and dispersion. The deviation suffered by the red color in the incident white light is less as compared with that of violet fight. Thus, instead of getting a point image of a point object, we get a colored image. Thus, the image is distorted. This failure of the lens to bring the rays of different colors to focus at the same point is called chromatic aberration.
(ii) Spherical aberration can be minimized by bending the lens into its best form. The use of symmetric doublets greatly reduces spherical aberration.
ISC Physics Question Paper 2012 Solved for Class 12 35
ISC Physics Question Paper 2012 Solved for Class 12 36

(c) (i) Resolving power of a simple telescope is defined as the ability of an simple telescope to separate point of an object that are located at a smaller angular distance. It is given by following expression:
\(\mathrm{P}_{\mathrm{R}}=\frac{120}{\mathrm{D}_{\mathrm{o}}}\left(\text { where } \mathrm{D}_{\mathrm{o}} \text { is in } \mathrm{mm}\right)\)
(ii) Reflecting telescope does not suffer from chromatic aberration because all wavelengths will reflect of the mirror in the same way which is not the case with refracting telescope.

Section-C
(Answer any two questions)

Question 8.
(a) Electrons having a velocity \(\vec{v}\) of 2 × 106 ms-1 pass undeviated through a uniform electric field \(\vec{E}\) of intensity 5 × 104 Vm-1 and a uniform magnetic field \(\vec{B}\) . [2]
(i) Find the magnitude of magnetic flux density B of the magnetic field. [2]
(ii) What is the direction of \(\vec{B}\), if \(\vec{v}\) is towards right and \(\vec{E}\) is vertically downwards in the plane of this paper ?

(b ) Monochromatic light of wavelength 198 nm is incident on the surface of a metal, whose work function is 2.5 eV. Calculate the stopping potential. [3]

(c) Energy levels of H atom are given by: [3]
\(\mathrm{E}_{n}=-\frac{13.6}{n^{2}} \mathrm{eV}\)
where n is Principal Quantum number. Calculate the wavelength of electromagnetic radiation emitted by hydrogen atom resulting from the transition: n = 2 to n = 1.
Answer:
ISC Physics Question Paper 2012 Solved for Class 12 37
ISC Physics Question Paper 2012 Solved for Class 12 38
ii) The electron will experience a force in the upward direction due to the electric field in the plane of the paper. Since the electron passes undeviated, the force due to the magnetic field will be in the downward direction. The direction of the: force on the electron will be in the down ward only if B is directed downward perpendicular to the plane of paper
\((\overrightarrow{\mathrm{F}_{m}}=-e(\vec{v} \times \overrightarrow{\mathrm{B}}))\)
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ISC Physics Question Paper 2012 Solved for Class 12 41
Question 9.
(a) (i) What is Compton effect ? [3]
(ii) In Coolidge X-Ray tube (Modem X-Ray tube) how will you vary :
(1) intensity of emitted X-Rays ?
(2) penetrating power of emitted X-Rays ?

(b) Complete the following table for a radioactive element whose half life is 5 minutes. Assume that you have 32 g of this element at start, i.e., at t = 0. [3]
ISC Physics Question Paper 2012 Solved for Class 12 42
Now, using this data, plot the “decay curve.”

(c) Calculate the energy released when an electron annihilates a positron. [2]
Answer:
(a) (i) Compton effect: It is the increase in wavelength of the electromagnetic radiation when these radiations are scattered by tree electrons or from elements of low atomic weight. Some of the energy of the incident photon is transferred to the electron due to which its wavelength increases.
(ii) (1) The intensity of the ejected X-rays depends upon the number of electrons striking the anti cathode which in its turn depends upon the heating current in the filament. Thus, the intensity of X-rays can be changed by changing the healing current or temperature.
(2) The penetrating power of the X-rays depends upon the accelerating voltage i.e., potential difference between the cathode and the anti cathode. More the accelerating voltage, more the penetrating power of the X-rays.

(b) The completed table is as given below : Half life of radioactive element is 5 minutes.
ISC Physics Question Paper 2012 Solved for Class 12 43
ISC Physics Question Paper 2012 Solved for Class 12 44
Question 10.
(a) Draw a labelled energy band diagram for a solid which is an insulator. What is the main difference between this diagram and that of a semiconductor ? [3]
(b) Figure below shows the circuit of an electronic device : [3]
ISC Physics Question Paper 2012 Solved for Class 12 45
(i) Which electronic device : a rectifier, an amplifier or an oscillator does the above circuit represent ?
(ii) State where the input voltage is applied and where the output voltage is available.
(iii) Compare the output voltage of this circuit with its input voltage.

(c) Prepare a truth table for the combination of gates shown in figure below : [2]
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ISC Physics Question Paper 2012 Solved for Class 12 47
Answer:
ISC Physics Question Paper 2012 Solved for Class 12 48
The main difference in energy band diagram of solid insulator and that of conductor is in case of insulator there is wide energy gap between valance band and conduction band whereas this gap is small in case of semiconductor.

(b) (i) This is the circuit diagram of a common emitter amplifier (using p-n-p transistor)
(ii) The input is applied in between AB and the output is obtained at load i.e., in between MN.
(iii) The output and input voltage of the given circuit has the phase difference of 180° i.e., there is a phase reversal as shown in the diagram alongside.
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(c) A study of the gates shows that it is a NAND gate followed by a NOT gate i.e., it represents a AND gate.
\(\overline{\mathrm{A} \cdot \mathrm{B}}=\mathrm{A} \cdot \mathrm{B}\)
Its truth table is as given below:
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ISC Class 12 Physics Previous Year Question Papers