Question

A source of sound gives five beats per second when sounded with another source of frequency `100s^-1`. The second harmonic of the source together with a source of frequency `205s^-1` gives five beats per second. What is the ferquency of the source?
A. `105s^-1`
B. `205s^-1`
C. `95s^-1`
D. `100s^-1`

Answer 1

Correct Answer - A
Frequency of the source `=100+-5=105Hz` or `95Hz`.
Second harmonic of the source `=210Hz` or `190Hz`. As the second harmonic gives 5 beats/sec with sound of frequency 205 Hz, the sound harmonic should be 210 Hz.
`implies`frequency of the source `=105Hz`