Question

The frequency of two tuning forks A and B are 1.5% more and 2.5% less than that of the tuning fork C. When A and B are sounded together, 12 beats are produced in 1 second. The frequency of tuning fork C is ______ 

Options

• 300 Hz

• 240 Hz

• 360 Hz

• 200 Hz

Answer 1

The frequency of two tuning forks A and B are 1.5% more and 2.5% less than that of the tuning fork C. When A and B are sounded together, 12 beats are produced in 1 second. The frequency of tuning fork C is 300 Hz.

Explanation:

f_A = f_c × 1.015

f_B = f_c × 0.975

f_A - f_B = 12

(1.015 - 0.975) f_c = 12

0.040f_c = 12

∴ f = `12/0.040` = 300 Hz