1. Velocity of sound in air is
a) Faster in dry air than in moist air
b) Directly proportional to pressure
c) Directly proportional to temperature
d) Independent of pressure of air
Explanation:
2. Two monoatomic ideal gases 1 and 2 of molecular
masses \[m_{1}\] and \[m_{2}\] respectively are enclosed in
separate containers kept at the same
temperature. The ratio of the speed of sound in
gas 1 to that in gas 2 is given by
a) \[\sqrt{\frac{m_{1} }{m_{2} }}\]
b) \[\sqrt{\frac{m_{2} }{m_{1} }}\]
c) \[\frac{m_{1}}{m_{2}}\]
d) \[\frac{m_{2}}{m_{1}}\]
Explanation:
3. A man is standing between two parallel cliffs and
fires a gun. If he hears first and second echoes
after 1.5 s and 3.5s respectively, the distance
between the cliffs is (Velocity of sound in air =340 m \[s^{-1}\] )
a) 1190 m
b) 850 m
c) 595 m
d) 510 m
Explanation:
4. When the temperature of an ideal gas is increased
by 600 K, the velocity of sound in the gas becomes
\[\sqrt{3}\] times the initial velocity in it. The initial
temperature of the gas is
a) \[-73^{\circ}C\]
b) \[27^{\circ}C\]
c) \[127^{\circ}C\]
d) \[327^{\circ}C\]
Explanation:
5. The frequency of a sound wave is n and its
velocity is v. If the frequency is increased to 4 n,
the velocity of the wave will be
a) v
b) 2 v
c) 4 v
d) v /4
Explanation: Velocity of sound is independent of frequency. Therefore it is same (v) for frequency n and 4n.
6. The temperature at which the speed of sound in
air becomes double of its value at \[27^{\circ}C\] is
a) \[54^{\circ}C\]
b) \[327^{\circ}C\]
c) \[927^{\circ}C\]
d) \[-123^{\circ}C\]
Explanation:
7. The speed of a wave in a certain medium is 960
m/s. If 3600 waves pass over a certain point of
the medium in 1 minute, the wavelength is
a) 2 metres
b) 4 metres
c) 8 metres
d) 16 metres
Explanation:
8.Speed of sound at constant temperature depends
on
a) Pressure
b) Density of gas
c) Above both
d) None of the above
Explanation: Speed do sound, doesn’t depend up on pressure and density medium
9.A man standing on a cliff claps his hand hears its
echo after 1 sec. If sound is reflected from another
mountain and velocity of sound in air is 340
m/sec. Then the distance between the man and
reflection point is
a) 680 m
b) 340 m
c) 85 m
d) 170 m
Explanation: If d is the distance between man and reflecting surface of sound then for hearing echo
10.What will be the wave velocity, if the radar gives
54 waves per min and wavelength of the given
wave is 10 m
a) 4 m/sec
b) 6 m/sec
c) 9 m/sec
d) 5 m/sec
Explanation:
