A point source emits sound equaly in all directions in a non-absorbing medium,. Two points P and Q are at distance of 2m and 3m respectively from the source. The ratio of the intensities of the waves at P and Q is
9 : 4
2 : 3
3 : 2
4 : 9
A sonometer wire when vibrated in full lentgth has frequency n. Now it is divided by the help of bridges into a number of segments of lengths l1, l2, l3,........When vibrated these segments have frequencies n1, n2, n3,.........then the correct relation is
n =n1 + n2 + n3 + .........
n2 = n12 + n22 +n32+...........
The speed of a wave on a medium is 760 m/s. If 3600 waves are passing through a point in the medium in 2 minutes, then their wavelengths are
13.8 m
25.3 m
41.5 m
57.2 m
The frequency of sinusoidal wave, 0.40 cos (2000t +0.80) would be
2000 Hz
20 Hz
Two waves are approaching each oher with a velocity of 20 m/s and frequency n. The distance between two consecutive nodes is
A star which is emitting radiation at a wavelength of 5000 is approaching the earth with a velocity of 1.50 x106 m/s. The change in wavelength of the radiation as received on the earth is
The time of reverberation of a room A is one second. What wi be the time (in second) of reverberation of a room, having a the dimensions double of those of room A ?
2
4
1
Two waves are said to be coherent, if they have
same phase but different amplitude
same frequency but different amplitude
same frequency, phase and amplitude
different frequency, phase and amplitude
The equation of a sound wave is given as y = 0.005 sin (62.4x+ 316t ). The wavelength of this wave is
0.4 unit
0.3 unit
0.2 unit
0.1 unit
Each of the two strings of length 51.6 cm and 49.1 cm are tensioned separately by 20 N force. Mass per unit length of both the strings is same and equal to 1 gm-1. When both the strings vibrate simultaneously the number of beats is
5
7
8
3
