electric current and magnetism - Category wise Question and Answer Practice Test with Solutions

Question : 1 [NDA]

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

Question : 2 [NDA]

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 : 3 [NDA]

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 : 4 [NDA]

In the figure shown below, $L_1$ and $L_2$ are two lenses and are kept along the same axis. A parallel beam of light falling on $L_1$ leaves $L_2$ as a parallel beam: Consider the following statements.

1. Both L1 and L2 can be convex lenses.
2. The distance between the two lenses can be equal to sum of their focal lengths.

a) Both 1 and 2

b) Only 1

c) Only 2

d) Neither 1 nor 2

Question : 5 [UPPCS (Pre) 2007]

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