set 4 MCQ Questions & Answers Detailed Explanation

Question : 1

A composite disc is to be made using equal masses of aluminium and iron so that it has as high a moment of inertia as possible. This is possible when

a) the whole of the iron is kept in the core and the aluminium at the outer rim of the disc

b) the whole of aluminium is kept in the core and the iron at the outer rim of the disc

c) the surfaces of the disc are made of iron with aluminium inside

d) the whole disc is made with thin alternate sheets of iron and aluminium

Question : 2

A parachutist jumps from a height of 5000 metre. The relationship between his falling speed, v and the distance fallen through d is best represented as :

a)

b)

c)

d)

Question : 3

No work is done when

a) there is no component of force parallel to the direction of motion

b) a box is pushed along a horizontal floor

c) a nail is plugged into a wooden board

d) there is no component of force normal to the direction of force

Question : 4

If a running boy jumps on a rotating table, which of the following is conserved?

a) Angular momentum

b) K.E

c) Linear momentum

d) None of these

Question : 5

A coin is placed on a rotating disc and is stationary w.r.t. the disc, then the direction of friction is

a) towards the centre of the disc

b) opposite to the direction of motion of the coin w.r.t. ground

c) along the direction of motion of the coin w.r.t. ground

d) away from the centre of the disc

Question : 6

A fan is moving around its axis, What will be its motion regarded as ?

a) Skidding

b) Rolling with shipping

c) Pure rolling

d) Pure rotation