the wavelengths of two waves are 50 and 51 cm respectively. If the temperature of the room is `20^(@)` C, then what will be the number of beats produced per second by these waves, when the speed of sound at `0^(@)` C is 332 m/s ?

Options

A. 14
B. 10
C. 24
D. none of these

Answer

A

Explanation

`(v_(20))/(332) = sqrt((293)/(273))`
`v_(0) = 332 sqrt((293)/(273)) = 332 xx 1.036 = 344 ms^(-1)`
`n_(1) = (344 xx 100)/(50) = 688` Hz.
`n_(2) = (344 xx 100)/(51) = 674 ` Hz.
`therefore` No. of beats /sec = 688 - 674 = 14 .
correct choice is (a) .