A student performed the experiment to measure the speed of sound in air using resonance air-column method. Two resonances in the air-column were obtained by lowering the water level. The resonance with the shorter air-column is the first resonance and that with the longer air-column is the second resonance. Then,

Options

A. the intensity of the sound heard at the first resonance was more than at the second resonance
B. the prongs of the tuning fork were kept in a horizontal plane above the resonance tube
C. the ampitude of vibration of the end of the prongs is typically around `1 cm`
D. the length of the air-column at the first resonance was somewhat than `1//4` th of the wavelength of the sound in air.

Answer

A, D

Explanation

(A) The intensity of sound decreases with increases of order. The inisitu of sound is maximum for first resonance.
(B) The prongs vibrate in vertical plane.
(c) The prongs does not vibrate in amplitude of that order.
(D) Consider end correction, the length of air column is slightly less than `lambda//4`