set 8 MCQ Questions & Answers Detailed Explanation

Question : 1

The radius of curvatute of the plane mirror is

a) Infinity

b) One

c) Zero

d) Between one and infinity

Question : 2

A noise level of 100 decibel would correspond to

a) Ordinary conversation

b) Sound from a noisy street

c) Just audible sound

d) Noise from a machine shop

Question : 3

Total internal reflection can take place only if

a) the refractive indices of the two media are close to different

b) light goes from optically rarer medium (smaller refractive index) to optically denser medium

c) light goes from optically denser medium to rarer medium

d) the refractive indices of the two media are widely different

Question : 4

A watch shows times as 3 : 25 when seen through a mirror, time appeared will be

a) 7 : 35

b) 8 : 35

c) 9 : 35

d) 8 : 25

Question : 5

A solid is melted (above the melting point) and allowed to cool down at normal condition.Its variation of temperature as a function of times is as shown in the figure given below. What is the reason for the plateau(flat position) in the central region of the cooling curve as shown in the figure?

a) Specific heat of the solid

b) Latent heat of fusion of the solid

c) Thermal conductivity of the solid

d) Thermal capacity of the solid.

Question : 6

Ventilators are provided at the top of room

a) to maintain conventional currents to keep the air fresh in the room

b) to bring oxygen for breathing

c) so that sunlight may enter the room

d) to provide an outlet for carbon dioxide