A tuning fork of frequency 512 Hz makes 4 beats per second with the vibrating string of a piano. The beat frequency decreases to 2 beats per sec when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was

Options

(a) 510 Hz
(b) 514 Hz
(c) 516 Hz
(d) 508 Hz

Correct Answer:

508 Hz

Explanation:

The frequency of the piano string = 512+-4 = 516 or 508. When the tension is increased, beat frequency decreases to 2, it means that frequency of othe string is 508 as frequency of string increases with tension.