Deck 9: Waves and Light

Question 1

The force which tries to bring the body back to its mean position is called

A)deforming force
B)restoring force
C)gravitational force
D)buoyant force

Answer 1

restoring force

Question 2

In which of the following media will sound travel the fastest?

A)solid
B)both solid and liquid
C)liquid
D)gas

Answer 2

solid

Question 3

Sound waves in air are _____ waves.

A)longitudinal
B)radio
C)transverse
D)electromagnetic

Answer 3

longitudinal

Question 4

Sound waves cannot pass through

A)a solid-liquid mixture
B)an ideal gas
C)a liquid-gas mixture
D)a perfect vacuum

Question 5

Out of the following, which frequency is not clearly audible to the human ear?

A)30 Hz
B)30,000 Hz
C)300 Hz
D)3000 Hz

Question 6

The distance between two consecutive crests is L, then the wavelength is given by

A)L/2
B)2 L
C)4 L
D)L

Question 7

The frequency of a wave is 5 Hz. It refers to (type of wave)

A)ultrasonics
B)microwaves
C)infrasonics
D)radio waves

Question 8

A pulse is a wave

A)of high duration
B)of short duration
C)which travels in vacuum only
D)which travels in solids only

Question 9

Which of the following types of waves is different from others?

A)Light waves
B)X-rays
C)Radio waves
D)Sound waves

Question 10

Waves produced by supersonic jet planes are

A)shock waves
B)seismic waves
C)infrasonics
D)none of these

Question 11

Echo is produced due to

A)reflection of sound
B)refraction of sound
C)resonance
D)none of these

Question 12

SONAR is based on the principle of

A)echo
B)resonance
C)reverberation
D)any one of the above

Question 13

Which of the following frequencies of sound cannot be heard by human beings?

A)5 Hz
B)20 Hz
C)400 Hz
D)1000 Hz

Question 14

The mirror used in automobiles to see the rear field of view is

A)concave
B)convex
C)plane
D)none of these

Question 15

The mirror used in search lights is

A)concave
B)convex
C)plane
D)none of these

Question 16

Shaving mirrors are

A)convex mirrors
B)concave mirrors
C)plane mirrors
D)none of these

Question 17

The laws of reflection are true for

A)the plane mirror only
B)the concave mirror only
C)the convex mirror only
D)all reflecting surfaces

Question 18

When the object is at focus of a concave mirror, the image is formed at

A)focus
B)centre of curvature
C)within focus
D)infinity

Question 19

Which of the following is a non-luminous body?

A)fire
B)sun
C)stars
D)earth

Question 20

A body which allows most of the light to pass through it is called a

A)transparent body
B)opaque body
C)translucent body
D)none of these

Question 21

During the 19th century, light was considered to be a stream of particles called

A)atoms
B)electrons
C)corpuscles
D)quantas

Question 22

Who first proposed that light was wave-like in character?

A)Huygens
B)Newton
C)Young
D)Maxwell

Question 23

The screen behind the eye lens is called the

A)iris
B)ciliary muscle
C)retina
D)pupil