Sound Wave Front

Q. As a wave propagates,

1. The wave intensity remains constant for a plane wave.
2. The wave intensity decreases as the inverse of the distance from a line source.
3. The wave intensity decreases as the inverse square of the distance from a point source.
4. Total intensity of the spherical wave over the spherical surface centered at the source remains constant at all times

Q. If the source is moving towards right, wave-front of sound waves get modified to

1. 
2. 
3. None of these
4. 

Q. For a point source, linear source and source situated at infinite, the shape of wave front is respectively:-

1. Spherical, cylindrical, plane
2. Cylindrical, spherical, plane
3. Plane, spherical, cylindrical
4. Spherical, plane, cylindrical

Q. Which of the following is conserved when light waves interfere?

1. momentum
2. amplitude
3. energy
4. intensity

Q. Shown in the figure, are three waves originating from a point source. Points $A,B,C$ lie on trough while points $D,E,F$ lie on crest of the wave. A wavefront emitting from $O$ may pass through,

1. $A,B,F$
2. $\text{Either}A,D,E\text{or}B,C,F$
3. $\text{Either}A,E,C\text{or}B,D,F$
4. $\text{Either}A,B,C\text{or}D,E,F$

Q. Match list A and list B accurately :
List A List B
a) spherical wave front e) linear source
b) plane wave front f) point light source
c) cylindrical wave front g) at infinite distance

1. ( a, f ); ( b, e); ( c, g)
2. ( a, f ); ( b, g); ( c, e)
3. ( a, g ); ( b, f); ( c, e)
4. ( a, e ); ( b, g); ( c, f)

Q. If the source is moving towards right, wave-front of sound waves get modified to

1. 
2. 
3. 
4. None of these

Q. In, which of the following the interference is produced by the division of wave front?

1. Fresnel's bi-prism
2. Young's double slit experiment
3. Colours of thin film
4. Lloyd's mirror

Q. The points moving upward is/are

1. c
2. g
3. f
4. a

Q. Huygen's concept of secondary wave

1. allows us to find the focal length of a thick lens
2. is used to explain polarization
3. is a geometrical method to find a wavefront
4. is used to determine the velocity of light

Q. What is meant by sound ranging ? Give one use of sound ranging.