mechanics (mass, force, acceleration, work, energy, momentum, velocity) - Category wise Question and Answer Practice Test with Solutions

Question : 6 [NDA]

A book is kept on the surface of a table. If the gravitational pull of the earth on the book is the force of action, then the force of reaction is exerted by

a) the table on the book

b) the book on the earth

c) the book on the table

d) the table on the earth

Question : 7

The potential energy of a freely falling object decreases progressively.

a) Sum of Potential Energy and Kinetic Energy at any point during the free fall remains constant

b) Potential energy gets converted into kinetic energy progressively

c) The law of conservation of energy is violated

d) Both (a) and (b)

Question : 8

An electrical appliance of 500 W is used for 5 hours per day. Energy consumed in 30 days will be

a) 75 kW h

b) 25 kW h

c) 2.5 kW h

d) None of these

Question : 9

A car is moving on a road and rain is falling vertically. Select the correct answer.

a) The rain will strike both the screens

b) The rain will strike the front screen only

c) The rain will strike the wind screen only

d) The rain will not strike any of the screens

Question : 10 [IAS Prelim]

The working principle of a washing machine is :

a) reverse osmosis

b) dialysis

c) centrifugation

d) diffusion