Question

In resonance tube experiment, first resonance occurs for the length of air - column equal to 25 cm with a tuning fork of frequency 340 Hz. If the length of the air column is decreased by 1cm , the frequency of beats will be
A. 28Hz
B. 7Hz
C. 14Hz
D. 9Hz

Answer 1

Correct Answer - C
`n_2/n_1 = l_1/l_2 = 25/24`
`(n_2-n_1)/(n_1) = (25-24)/(24)`
`n_2-n_1 = 340/24 = 14`