Two tuning forks,A and B produce notes of frequencies 258 Hz and 262 Hz.An unknown note sounded with A produces certain beats.When the same note is sounded with B ,th beat frequeny gets doubled.The unknown frequency

Options

A. 250 Hz
B. 252 Hz
C. 254 Hz
D. 256 Hz

Answer

C

Explanation

Here `,v_(A)`=258 Hz,`v_(B)`=262 Hz Let the frequency of unknown tuning fork be v.
It produces `v_(b)` beats with A and `2v_(b)` with B. Therefore,
`v_(A)-v=v_(b)`……….(i)
and `v_(B)-v=2V_(b)`…..(ii)
Substituting the given value ,we get
262-258 =`V_(b)`
`V_(b)`=4Hz
From (i),`v=v_(A)-v_(b)`=(258-4)=254 Hz