Wave Mechanics Question 900

Question: Two tuning forks A and B give 4 beats per second. The frequency of A is 256 Hz. On loading B slightly, we get 5 beats in 2 seconds. The frequency of B after loading is

[Haryana CEE 1996]

Options:

A) 253.5 Hz

B) 258.5 Hz

C) 260 Hz

D) 252 Hz

Show Answer

Answer:

Correct Answer: C

Solution:

nA = Known frequency = 256 Hz, nB = ? x = 4 beats per sec which is decreasing (4 bps to ) after loading (i.e. x¯) Unknown tuning fork B, is loaded so nB¯ Hence nA ? nB¯ = x¯ … (i) Wrong nB¯ ? nA = x¯ … (ii) Correct

Therefore nB = nA + x = 256 + 4 = 260 Hz.