Question

A long glass tube is held vertically in water . A tuning fork is struck and held over the tube . Strong resonances are observed at two successive lengths `0.50 m and 0.84 m` above the surface of water . If the velocity of sound is `340 m//s`, then the frequency of the tuning fork is
A. `128 Hz`
B. `256 Hz`
C. `384 Hz`
D. `500 Hz`

Answer 1

Correct Answer - D
` lambda = 2( x_(2) - x_(1)) = 2 (0.84 - 0.50) = 0.68`
` n = (v)/(lambda) = ( 340)/( 0.68) = 500 Hz`