set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

If the earth rotates faster than its present speed, the weight of an object will

a) remain unchaged at the equator but decrease at the poles

b) decrease at the equator but remain unchanged at the poles

c) increase at the equator but remain unchaged at the poles

d) remain unchanged at the equator but increase at the poles

Question : 2

Two identical particles move towards each other with velocity 2v and v respectively. The velocity of centre of mass is

a) v/2

b) v/3

c) v

d) zero

Question : 3

A person is sitting in a car which is at rest. The reaction from the road at each of the four wheels of the car is R. When the car runs on a straight level road, how will the reaction at either of the front wheels vary?

a) It will be equal to R

b) It will be less than R

c) It will be greater than R

d) It shall depend on the material of the road

Question : 4

The maximum kinetic energy of a planet moving around the sun is at a position

a) C

b) B

c) A

d) D

Question : 5

Ball bearings are used in bicycles, cars, etc., because

a) the effective area of contact between the wheel and axle is reduced

b) the effective area of contact between the wheel and axle is increased

c) the actual area of contact between the wheel and axle is increased

d) None of the above statements is correct

Question : 6

Statement A :
When a gun is fired it recoils, i.e., it pushes back, with much less velocity than the velocity of the bullet.
Statement B :
Velocity of the recoiling gun is less because the gun is much heavier than the bullet.

a) Both statements are correct.

b) Statement B is correct.

c) Statement A is correct.

d) Both statements are incorrect.