set 4 MCQ Questions & Answers Detailed Explanation

Question : 1

In electric apparatus ‘Earth’ is used

a) For safety

b) To reduce the expenditure

c) Because the apparatus used 3-phase

d) In the form of fuse

Question : 2

An electric bulb is connected to 220 V generator. The current is 0.5A. The power of the bulb is

a) 440 W

b) 110 W

c) 110 V

d) 220 W

Question : 3

Fluorescent tubes are fitted with a choke. The choke coil

a) Reduces current in the circuit

b) Steps up the line voltage

c) Steps down the line voltage

d) Chokes low frequency current

Question : 4

A refracting telescope consists of

a) two concave mirrors of different focal lengths

b) one concave mirror and one convex lens

c) two convex lenses of equal focal length

d) two convex lenses of unequal focal lengths

Question : 5

What is the phenomenon of the moon to appear bigger in size as it approaches the horizon, called ?

a) Scattering of light

b) Atmospheric refraction of light

c) Diffraction of light

d) Total internal reflection of light by water vapours

Question : 6

When light waves travel from air to glass, which variables are affected?

a) Wavelength and frequency only

b) Wavelength, frequency and velocity

c) Velocity and frequency only

d) Wavelength and velocity only