The time of reverberation of a room A is one second. What will be the time (in second) of reverberation of a room, having all the dimensions double of those of room A?
2
4
1
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
Two strings A and B have lengths lA and lB and carry masses MA and MB at their lower ends, the upper ends being supported by rigid supports. If nA and nB are the frequencies of their vibrations and nA = 2nB, then:
lA = 4lB, regardless of masses
lB = 4lA, regardless of masses
MA = 2MB, lA = 2lB
MB = 2MA, lB = 2lA
Two waves of wavelength 50cm and 51 cm produce 12 beats/s. The speed of sound is:
306 m/s
331 m/s
340 m/s
360 m/s
A whistle revolves in a circle with angular velocity ω = 20 rad/s using a string of length 50 cm. If the actual frequency of sound from the whistle is 385 Hz, then minimum frequency heard by the observer far away from the centre is: (velocity of sound v = 340 m/s)
385 Hz
374 Hz
394 Hz
333 Hz
Two vibrating tuning forks produce progressive waves given by y1 = 4 sin 500 πt and y2 = 2 sin 506 πt. Number of beats produced per minute is:
360
180
3
60
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
Two sound waves with wavelengths 5.0 m and 5.5 m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats per second:
12
zero
6
Velocity of sound waves in air is 330 m/s. For a particular sound wave in air, path difference of 40 cm is equivalent to phase difference of 1.6 π. The frequency of this wave is:
165 Hz
150 Hz
660 Hz
330 Hz
Which one of the following statements is true?
Both light and sound waves in air are transverse
The sound waves in air are longitudinal while the light waves are transverse
Both light and sound waves in air are longitudinal
Both light and sound waves can travel in vacuum