10 question-answer of wave motion | Learn Physics

10 question-answer of wave motion

1.       When a sound wave goes from one medium to another, the quantity that remains unchanged:

(a)    Frequency

(b)   Amplitude

(c)    Wavelength

(d)   Speed

                Ans: ( a)

2.       Water waves are:

(a)    Longitudinal

(b)   Transverse

(c)    Both longitudinal and transverse

(d)   Neither  longitudinal nor transverse

                Ans: (c)

3.       In a gas, velocity of sound in air at 10 atmospheric pressure and at 1 atmospheric pressure will be in the ratio

(a)    10 : 1

(b)   1 : 10

(c)    1 : 1

(d)   Cannot say

                Ans: (c)

4.       Human ear cannot hear those mechanical waves whose frequency  lies in the frequency range:

(a)    Less than 100 Hz but greater  than 10000 hz

(b)   Between 1000 hz and 5000 hz

(c)    Between 500 hz and 20000 hz

(d)   Less than 16 hz and more than 200000 hz

               Ans:( d)

5.       The distance between two consecutive crests in a wave train produced in a string is 5 cm. if 2 complete waves pass through any point per second, the velocity of the wave is:

(a)    10 cm/sec

(b)   2.5 cm/sec

(c)    5 cm/sec

(d)   15 cm/sec

               Ans: ( a)

6.       A plane wave of sound travelling in air is incident upon a plane water surface. The angle of incidence is 30˚. If the velocity of sound in water is 1400 m/s, and the velocity of sound in air is 330 m/s, there will be:

(a)    Reflection only

(b)   Refraction only

(c)    Both reflection and refraction

(d)   Neither  reflection nor refraction

              Ans: (a)

7.       A balloon is filled with hydrogen. For sound waves, the balloon behaves like:

(a)    A converging lens

(b)   A diverging lens

(c)    A concave mirror

(d)   Nothing can be said

              Ans: ( b)

8.       The ratio of intensities of sound wave A and B is 1000 :  1. Then intensity level of A is greater than intensity level of B by:

(a)    1000 times

(b)   10 times

(c)    3 times

(d)   2 times

              Ans: ( c)

9.       With the propagation of a longitudinal wave through a material medium, the quantities transmitted in the propagation direction are:

(a)    Energy , momentum and mass

(b)   Energy

(c)    Energy and mass

(d)   Energy and linear momentum

              Ans: ( b)

10.       A sound wave is passing through an air column. During the consequent compressions and rarefractions:

(a)    Bulk modulus of air oscillates

(b)   Density remains constant

(c)    Boyle’s law is obeyed

(d)   Total amount of heat remains constant

               Ans: ( d)