Two sounding bodies producing progressive waves given by 


are situated very near to the ears of a person who will hear


Correct option is

2 beats per second with intensity ratio 49/1between maxima and minima.


The two amplitude of the two sounds are a1 = 4 units and a2 = 3 units. Their angular frequencies are ω1 = 400 π rad s–1 and ω2 = 404 π rad s–1. Therefore, their frequencies are V1 = 200 Hz and V2 = 202 Hz. Hence the beat frequency = V2 – V1 = 2 Hz, i.e. the person will hear 2 beats per second. The intensity ratio is given by





A wave is represented by the equation  


Where x is in metres and t in seconds. The expression represents


A stretched string of length 1 m, fixed at both ends, having a mass of  kg is under a tension of 20 N. It is plucked at a point situated at 25 cm from one end. The string would vibrate with a frequency of


Two bodies M and N of equal masses are suspended from two separate springs of force constants k1 and k2 respectively. If they oscillate with equal maximum velocities, the amplitudes of M and N will be the ratio of


A sonometer wire is in unison with a tuning fork. Keeping the tension unchanged, the length of the wire between the bridge is doubled. The tuning fork can still be in resonance with the wire, provided the wire now vibrates in


A source of sound emitting a note of frequency 200 Hz moves towards an observer with a speed v equal to the speed of sound. If the observer also moves away from the source with the same speed v, the apparent frequency heard by the observer is


The difference between the apparent frequencies of a source of sound as perceived by an observer during its approach and recession is 2% of the actual frequency of the source. If the speed of sound in air is 300 ms–1, the speed of the source is


A tuning fork of frequency 480 Hz produces 10 beats per second when sounded with a vibrating sonometer string. What must have been the frequency of the string if a slight increase in the tension of the string produces fewer beats per second than before?


A train blowing its whistle moves with a constant velocity u away from the observer on the ground. The ratio of the actual frequency of the whistle to that measured by the observer is found to be 1.2. If the train is at rest and the observer moves away from it at the same velocity, the ratio would be given by


The intensity of sound gets reduced by 20% on passing through a slab. The reduction in intensity on passage through two consecutive slabs is


An organ pipe P1, closed at one end vibrating in its first harmonic and another pipe P2, open at both ends vibrating in its third harmonic, are in resonance with a given tuning fork. The ratio of the lengths of P1 and P2is