Two trains move towards each other with the same speed. The speed of sound is 340 m/s. If the height of the tone of the whistle of one of them heard on the other changes times, then the speed of each train should be
20 m/s
2 m/s
200 m/s
2000 m/s
A stretched string resonates with tuning fork frequency 512 Hz when length of the string is 0.5 m. The length of the string required to vibrate resonantly with a tuning fork of frequency 256 Hz would be
0.25 m
0.5 m
1 m
2 m
A hospital uses an ultrasonic scanner to locate tumours in a tissue. The operating frequency of the scanner is 4.2 MHz. The speed of sound in a tissue is 1.7 km/s. The wavelength of sound in tissue is close to
4 x 10-4 m
8 x 10-4 m
4 x 10-3 m
8 x 10-3 m
With the propagation of a longitudinal wave through a material medium, the quantities transmitted in the propagation direction are
energy, momentum and mass
energy
energy and mass
energy and linear momentum
For production of beats the two sources must have
different frequencies and same amplitude
different frequencies
different frequencies, same amplitude and same phase
different frequencies and same phase
If the amplitude of sound is doubled and the frequency reduced to one-fourth, the intensity of sound at the same point will
increase by a factor of 2
decrease by a factor of 2
decrease by a factor of 4
remains unchanged
Which of the following equation represents a wave?
y = a sin ωt
y = a cos kx
y = a sin (ωt - bx + c)
y = a sin (ωt - kx)
The speed of a wave in a medium is 760 m/s. If 3600 waves are passing through a point in the medium in 2 min, then their wavelength is
13.8 m
25.3 m
41.5 m
57.2 m
The velocity of sound in any gas depends upon
wavelength of sound only
density and elasticity of gas
intensity of sound waves only
amplitude and frequency of sound
The frequency of sinusoidal wave, 0.40 cos (2000t + 0.80) would be
1000π Hz
2000 Hz
20 Hz
