In the sonometer experiment , a tuning fork of frequency `256 Hz` is in resonance with `0.4 m` length of the wire when the iron load attached to free end of wire is `2 kg`. If the load is immersed in water , the length of the wire in resonance would be ( specific gravity of iron ` = 8`)

Options

A. `0.37 m`
B. `0.43 m`
C. `0.31 m`
D. `0.2 m`

Answer

A

Explanation

`(sqrt(T))/(l) =` constant , tension decreases by a factor `( 8 - 1)//8`, length decreases by a factor square root of this , i.e., ` sqrt( 7//8) = 0.93`