KCET2015PhysicsLaws of Motion
When two tuning forks ( A ) and ( B ) are sounded together. ( 4 ) beats per second are heard. The frequency of the fork ( B ) is ( 384 ~Hz ). When one of the prongs of the fork ( A ) is filed and sounded with ( B ), the beat frequency increases, then the frequency of the fork ( A ) is
Options
- A( 380 ~Hz )
- B( 388 ~Hz )
- C( 379 ~Hz )
- D( 389 ~Hz )
Correct answer
B. ( 388 ~Hz )
Step-by-step solution
Given, beat frequency =4 beats per second; frequency of fork B=384 ~Hz Now, we know beat frequency f_ A -f_ B Here f_ A is frequency of fork A ; f_ B is frequency of fork B 4=f_ A -384 f_ A =4+384=388 Therefore, frequency of the fork A is 388 ~Hz .