set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

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.
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a) (A) is true, but (R) is false

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

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 2

If a light body and a heavy body have equal momentum, then

a) the kinetic energy of the lighter body is equal to the kinetic energy of the heavier body

b) the lighter body has lesser kinetic energy than the heavier body

c) the lighter body has greater energy than the heavier body

d) the kinetic energy of both the bodies are independent of momentum.

Question : 3

Consider the following statements :

1. Copernicus discovered that the earth moves around the sun.
2. An astronaut cannot use a straw to sip a drink on the surface of the moon.
3. The S.I. unit of weight is kilogram.

a) 2 and 3

b) 1 and 2

c) 1 and 3

d) 1, 2 and 3