Velocity of sound waves in air is 330 m/sec. For a particular sound in air, a path difference of 40 cm is equivalent to a phase difference of 1.6 . The frequency of this wave is -
A stone is dropped in a well which is 19.6m deep. Echo sound is heard after 2.06 sec (after dropping) then the velocity of sound is -
A tuning fork of frequency 340 s–1 vibrates just above a cylindrical tube. Height of tube is 120 cm. If velocity of sound is 340 ms–1, the least height in cm of water required for resonance is -
In case of standing waves -
Which of the following travelling wave will produce standing wave, with node at x = 0, when superimposed in y = Asin (ωt – kx) -
The sound level of the chirping made by a bird at a distance of 5 metres is measured at 30 dB. When the same bird is 50 metres away, the sound level is measured at 10 dB. How many times greater is the amplitude of the sound wave at 5 metres away compared to 50 metres away -
The velocities of sound at the same temperature in two monoatomic gases of densities ρ1 and ρ2 and v1 and v2 If ρ1/ρ2 = 4, then the value of v1/ v 2 is -
An observer standing at the seacoast observes 54 waves reaching the coast per minute. If the wavelength of the waves is 10 m, its velocity is -
A sound wave of wavelength 90 cm in glass is refracted into air. If the velocity of sound in glass is 5400 m/sec, the wavelength of the wave in air is -
A boat at anchor is rocked by waves whose crests are 100 m apart and velocity is 25 m/s. The boat bounces up once in every -
A tuning fork gives 4 beats with 50 cm length of a sonometer wire. If the length of the wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is -
In a large room, a person receives direct sound waves from a source 120 metre away from him. He also receives waves from the same source which reach, being reflected from the 25 metre high ceiling, at a point halfway between them. The two waves interfere constructively for a wavelength of -
When two tuning forks A and B are sounded together, x beats/sec are heard. Frequency of A is n. Now when one prong of fork B is loaded with a little wax, the number of beats/sec decreases. The frequency of fork B is -
Two organ pipes, each closed at one end, gives5 beats per sec, when emitting their fundamental notes. If their lengths are in the ratio of 50 : 51, , their fundamental frequencies (in Hz) are -
In a resonance column experiment, the first resonance is obtained when the level of the water in the tube is at 20 cm from the open end. Resonance will also be obtained when the water level is at a distance of -
When we hear a sound, we can identify it from
The first overtone of an open organ pipe and the fundamental tone of a closed organ pipe give 5 beats per second when sounded together. If the length of the closed pipe is 25 cm, what are the possible lengths of the open organ pipe (Speed of sound in air = 340 m/sec) -
A closed organ pipe and an open organ pipe of same length produce four beats in their fundamental mode when sounded together. If length of the open organ pipe is increased, then the number of beats will
If the ratio of maximum to minimum intensity in beats is 49, then the ratio of amplitudes of two progressive wave trains is
Two interfering waves have intensities in the ratio 9 : 1. Then the ratio of maximum to minimum amplitude is -
The velocity of sound in air is 330 m/s. The r.m.s. velocity of air molecules ( = 1.4) is approximately equal to -
When a source of frequency f0 moves away a stationary observer with a certain velocity an apparent frequency f ' is observed. When it moves with same velocity towards the observer, the observed frequency is 1.2 f '. If velocity of sound in v, then the speed of source is -
A man is standing between source and cliff. When he start moving along line joining him and source, he hears 10 beats per second. Velocity of man is : (Frequency of source = 60 Hz, Velocity of sound = 330 m/s)
The apperent frequency of the whistle of an engine changes by the ratio 5/3 as the engine passes a stationary observer. If the velocity of sound is 340 m/s, then the velocity of the engine is -
