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Physics

105 questions in Science & Technology.

Asked in 2002, 2001, 2000, 1999

2001 · Q101Science & TechnologyPhysicsmoderate

Assertion (A): A stick is dipped in water in a slanting position. If observed sideways, the stick appears short and bent at the surface of water. Reason (R): The light coming from the stick undergoes scattering from water molecules giving the stick a short and bent appearance.

  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 a 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(c) A is true but R is false

2001 · Q102Science & TechnologyPhysicsmoderate

Assertion (A): A piece of copper and a piece of glass are heated to the same temperature. When touched, thereafter, the copper piece appears hotter than the glass piece. Reason (R): The density of copper is more than that of glass.

  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 a 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(c) A is true but R is false

2001 · Q110Science & TechnologyPhysicsmoderate

Consider the following statements: A simple pendulum is set into oscillation. Then I. The acceleration is zero when the bob passes through the mean position. II. In each cycle the bob attains a given velocity twice. III. Both acceleration and velocity of the bob are zero when it reaches its extreme position during its oscillation. IV. The amplitude of oscillation of the simple pendulum decreases with time. Which of these statements are correct?

  1. (a)I and II
  2. (b)III and IV
  3. (c)I, II and IV
  4. (d)II, III and IV
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Official answer(c) I, II and IV

2000 · Q103Science & TechnologyPhysicsmoderate

Assertion (A): A man standing on a completely frictionless surface can propel himself by whistling. Reason (R): If no external force acts on a system, its momentum cannot change.

  1. (a)Both A and R are true, and R is the correct explanation of A
  2. (b)Both A and R are true, but R is not a 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 true, and R is the correct explanation of A

2000 · Q104Science & TechnologyPhysicsmoderate

Assertion (A): In a motion picture, usually 24 frames are projected every second over the whole length of the film. Reason (R): An image formed on the retina of eye persists for about 0.1 s after the removal of stimulus.

  1. (a)Both A and R are true, and R is the correct explanation of A
  2. (b)Both A and R are true, but R is not a 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 true, and R is the correct explanation of A

2000 · Q105Science & TechnologyPhysicsmoderate

Assertion (A): Small glass beads fixed on traffic signals glow brightly when light falls upon them. Reason (R): Light is totally reflected when the angle of incidence exceeds a certain critical value and light travelling in a denser medium is reflected back into a rarer medium.

  1. (a)Both A and R are true, and R is the correct explanation of A
  2. (b)Both A and R are true, but R is not a 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 true, and R is the correct explanation of A

2000 · Q114Science & TechnologyPhysicsmoderate

Assertion (A): Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluorocarbons. Reason (R): Ammonia can be liquified at ambient temperatures at low pressures.

  1. (a)Both A and R are true, and R is the correct explanation of A
  2. (b)Both A and R are true, but R is not a 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 true, and R is the correct explanation of A