The frequency of sinusoidal wave, 0.40 cos (2000t + 0.80) would be
1000π Hz
2000 Hz
20 Hz
1000/π Hz
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
A stretched string resonates with tuning fork frequency 512 Hz when length of the string is 0.5m. The length of the string required to vibrate resonantly with a tuning fork of frequency 256 Hz would be.
0.25m
0.5m
1m
2m
A star which is emitting radiation at a wavelength of 5000 Å is approaching the earth with a velocity of 1.50 × 106 m/s. The change in wavelength of the radiation as received on the earth is
0.25 Å
2.5 Å
25 Å
250 Å
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 9/8 times, then the speed of each train should be
20 m/s
2 m/s
200 m/s
2000 m/s
What is the effect of humidity on sound waves when humidity increases?
Speed of sound wave increases
Speed of sound decreases
Speed of sound waves remains same
Speed of sound waves becomes zero.
Two waves are approaching each other with a velocity of 20m/s and frequency n. The distance between two consecutive nodes is
20/n
10/n
5/n
n/10
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 × 10-4m
8 × 10-4m
4 × 10-3m
8 × 10-3m
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)