Two tuning forks A and B gives 6 beat/s. The fork A resonates with a closed end air column of length 15cm and the fork B with an open air column of length 30.5cm . If the air in both the cases vibrates in the air fundamental modes, then the frequencies of fork A and B will be

Options

A. 354 and 360Hz
B. 366 and 360Hz
C. 360 and 354 Hz
D. 360 and

Answer

B

Explanation

Let `n_A "and " n_B` denotes the frequency of tuning fork A and B . Then
`n_A = (v)/(4(15)) = v/60 " and " n_B = (v)/(2(30.5)) = v/61`
As `n_A gt n_B " " therefore n_A -n_B = 6`
`v/60 - v/61 = 6 therefore v[(61-60)/(60xx61)]=6`
`n_A = v/60 = (6xx60xx61)/(60) = 366`
`n_B=v/61=(6xx60xx61)/(61) = 360Hz`