Question

When two tuning forks A and B are sounded together, 4 beats per second are head. The frequency of the fork B is 348 Hz. When one of the prongs of the fork A is filled and sounded with B, the beat frequency increases, then the frequency of the fork A is
A. 379 Hz
B. 380 Hz
C. 389 Hz
D. 388 Hz

Answer 1

Correct Answer - B
Given, frequency of fork `B, v_(B) = 384 Hz` when brongs of the fork A is filled than its frequency decreases.
`:. V_(B) - v_(A) = 4 rArr 384- v_(A) = 4`
`v_(A) = 384-4`
Frequency of fork `A, v_(A) = 380 Hz`