A hollow metallic tube a length L and closed at one end produces resonance with a tuning fork of frequency n. The entire tube is then heated carefully. So that at equilibrium temperature its length changes by `l`. If the change in velocity V of sound is v, the resonance will now be produced by tuning fork whose frequency is :

Options

A. `(V-v)/(4(L+l))`
B. `(V+v)/(4(L-l))`
C. `(V-v)/(4(L-l))`
D. `(V+v)/(4(L+l))`.

Answer

D