A tuning fork ' A ' produces 5 beats per second with a tuning fork of frequency 480 Hz . When a little wax is stuck to a prong of fork A , the number of beats heard per second becomes 2 . What is the frequency of tuning fork A before the wax is stuck to it?

Step-by-step solution

(D) Frequency of tuning fork B =480 ~Hz . It produces 5 beats with tuning fork A . Therefore frequency of tuning fork A can be 485 ~Hz or 475 ~Hz . On loading the tuning fork A with wax its frequency will decrease. Since the number of beats decreases, it means its frequency is higher than that of B. Hence its frequency is 485 ~Hz . #