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
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
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
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
Two waves of same frequency and intensity superimpose on each other in opposite phases. After the superposition, the intensity and frequency of waves will
increase
decrease
remain constant
become zero
A wave of frequency 100 Hz is sent along a string towards a fixed end. When this wave travels back after reflection, a node is formed at a distance of 10 cm from the fixed end of the string. The speed of incident ( and reflected) wave are
5 m/s
10 m/s
40 m/s
Two waves are approaching each other with a velocity of 20 m/s and frequency n. The distance between two consecutive nodes is
The transverse wave represented by the equation has
amplitude = 4π
speed of propagation = 5
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
From a wave equation
the frequency of the wave is
5 Hz
15 Hz
20 Hz
25 Hz
