Question

A tuning fork of frequency 200Hz is in unison with a sonometer wire . The number of beats heard per second when the tension is increased by 1% will be
A. 1
B. 2
C. 4
D. 0.5

Answer 1

Correct Answer - A
`T_2 = T_1 + 0.01T_1 = 1.01 T_1`
`n_1 prop sqrt(T_1) " and " n_2 prop sqrt(T_2)`
`n_2/n_1 = sqrt(T_2/T_1) = sqrt(1.01) = (1+0.01)^(1//2)`
`=1+1/2 xx0.01 = 1.005`
`n_1-n_2=0.005xx200=1`