Highly selective Backlog Qs for JEE MainPhysicsWaves and Sound
An organ pipe, open from both end produces 5 beats per second when vibrated with a source of frequency 200 ~Hz . The second harmonic of the same pipes produces 10 beats per second with a source of frequency 420 ~Hz . The fundamental frequency of organ pipe is
Options
- A195 ~Hz
- B205 ~Hz
- C190 ~Hz
- D210 ~Hz
Correct answer
B. 205 ~Hz
Step-by-step solution
Let the fundamental frequency of organ pipe be f Case I : f=200 5=205 ~Hz or 195 ~Hz Case II : frequency of 2 nd harmonic of organ pipe =2 f (as is clear from the second figure) 2 f =420 10 or f =210 5 or f =205 or 215 Hence fundamental frequency oforgan pipe =205 ~Hz