A long glass tube is held vertically , dipping into water, while a tuning fork of frequency `512 H_(Z)` is respeatedly struck and held over the open end. Strong resonance is obtained, when the length of the tube above the surface of water is `50 cm` and again `84 cm`, but not at any intermediate point. Find the speed of sound of sound in air and next length of the air column for resonance.

Answer

A, C, D

Explanation

`(lambda)/(2) = (84 - 50) cm = 34 cm`
Next length `= 84 + (lambda)/(2) = 118 cm`
`lambda = 68 cm` or `0.68 m`
`nu = f lambda = (512) (0.68)`
`= 348.16 m//s`