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Science & Technology

923 questions asked in UPSC Prelims.

2006 · Q95Science & TechnologyPhysicsmoderate

There are 8 equidistant points A, B, C, D, E, F, G and H in the clockwise direction on the periphery of a circle. In a time-interval t, a person reaches from A to C with uniform motion while another person reaches the point E from the point B during the same time-interval with uniform motion. Both the persons move in the same direction along the circumference of the circle and start at the same instant. How much time after the start will the two persons meet each other?

  1. (a)4t
  2. (b)7t
  3. (c)9t
  4. (d)Never
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Official answer(b) 7t

2006 · Q101Science & TechnologyQuantitative Aptitudedifficult

There are three parallel straight lines. Two points A and B are marked on the first line, points C and D are marked on the second line, and points E and F are marked on the third line. Each of these six points can move to any position on its respective straight line. Consider the following statements: 1. The minimum number of triangles that can be formed by joining these points is zero. 2. The maximum number of triangles that can be formed by joining these points is twenty. Which of the statements given above is/are correct?

  1. (a)1 only
  2. (b)2 only
  3. (c)Both 1 and 2
  4. (d)Neither 1 nor 2
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Official answer(c) Both 1 and 2

2006 · Q103Science & TechnologyLogical Reasoning & Puzzlesmoderate

In an office, the number of persons who take tea is twice the number of persons who take only coffee. The number of persons who take coffee is twice the number of persons who take only tea. Consider the following statements: 1. The sum of the number of persons who take either tea or coffee or both is four times the number of persons who take both coffee and tea. 2. The sum of the number of persons who take only coffee and those who take only tea is twice the number of persons who take both coffee and tea. Which of the statements given above is/are correct?

  1. (a)1 only
  2. (b)2 only
  3. (c)Both 1 and 2
  4. (d)Neither 1 nor 2
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Official answer(b) 2 only

2006 · Q123Science & TechnologyScience & Technology Historymoderate

Match List-I (Indian Scientist/Scholar) with List-II (Area of work) and select the correct answer using the code given below the lists: List I A. C. N. R. Rao B. Jagdish Bhagwati C. G. N. Ramchandran D. Ashok List II 1. Telecommunication 2. Physics 3. Economics 4. Solid State Chemistry and Material Science Code:

  1. (a)A-4 B-3 C-2 D-1
  2. (b)A-2 B-1 C-4 D-3
  3. (c)A-4 B-1 C-2 D-3
  4. (d)A-2 B-3 C-4 D-1
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Official answer(a) A-4 B-3 C-2 D-1

2005 · Q84Science & TechnologySpace Technology & Astronomymoderate

Assertion (A): Existence of human life on Venus is highly improbable. Reason (R): Venus has extremely high level of carbon dioxide in its atmosphere.

  1. (a)Both A and R are individually true and R is the correct explanation of A
  2. (b)Both A and R are individually true but R is not the correct explanation of A
  3. (c)A is true but R is false
  4. (d)A is false but R is true
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Official answer(a) Both A and R are individually true and R is the correct explanation of A

2005 · Q88Science & TechnologyEnergy & Environmenteasy

Assertion (A): The main constituent of the Liquefied Petroleum Gas is methane. Reason (R): Methane can be used directly for burning in homes and factories where it can be supplied through pipelines.

  1. (a)Both A and R are individually true and R is the correct explanation of A
  2. (b)Both A and R are individually true but R is not the correct explanation of A
  3. (c)A is true but R is false
  4. (d)A is false but R is true
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Official answer(d) A is false but R is true