A tuning fork of frequency 340 Hz is sounded above a cylindrical tube 1 m high. Water is slowly poured into the tube. If the speed of sound is 340 ms–1, at what levels of water in the tube will the sound of the fork be appreciably intensified? 


Correct option is

25 cm, 75 cm

Frequency of sound emitted by a closed pipe of length L in the fundamental mode is  For resonance V = V' where V' is the frequency of the tuning fork. Thus  or 4L = 1m or L = 25 cm. The next resonance occurs at 4/3 L = 1 m or L = 75 cm.



Two identical waves, each of frequency 10 Hz, are travelling in opposite directions in a medium with a speed of 20 cm s–1. The distance between adjacent nodes is


Figure shows the shape of part of a long string in which transverse waves are produced by attaching one end of the string to tuning fork of frequency 250 Hz. What is the velocity of the waves?




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The distance between a node and the next anti-node is


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An observer moves towards a stationary source of sound with a velocity one-tenth the velocity of sound. The apparent increase in frequency is


A stone hangs from the free end of a sonometer wire whose vibrating length, when tuned to a tuning fork, is 40 cm. When the stone hangs wholly immersed in water, the resonant length is reduced to 30 cm. The relative density of the stone is


A cylindrical tube, open at both ends, has fundamental frequency n. If one of the ends is closed, the fundamental frequency will become


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A progressive wave in a medium is represented by the equation 


Where y and x are in cm and t in seconds. The maximum speed of a particle of the medium due to the wave is


A sonometer wire, 65 cm long, is in resonance with a tuning fork of frequency N. If the length of the wire is decreased by 1 cm and it is vibrated with the same tuning fork, 8 beats are heard per second. What is the value of N?