Question

If two tuning forks A and B are sounded together, they produce 4 beats per second. When A is slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256 Hz. The frequency of B will be ______

Options

• 250 Hz

• 252 Hz

• 260 Hz

• 262 Hz

Answer 1

If two tuning forks A and B are sounded together, they produce 4 beats per second. When A is slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256 Hz. The frequency of B will be 252 Hz.

Explanation:

n_A = Known frequency = 256 Hz

Given that n_A ∼ n_B = 4

When A is loaded with wax, the number of beats reduces to 2 per second. As the frequency of the fork decreases after loading, n_A' < n_A. 

 ∴ correct equation is

n_A - n_B = 4 ⇒ n_B = 256 - 4 = 252 Hz