Question

A source X of unknown frequency produces 8 beats per second with a source of 250 Hz and 12 beats per second with a source of 270 Hz . The frequency of the source X is :

• A. 242 Hz
• B. 258 Hz
• C. 282 Hz
• D. 262 Hz

Answer 1

The correct option is B 258 Hz

Beats per second $=|{\nu }_x-{\nu }_y|$.
So from the first condition, we get ${\nu }_x=258\text{Hz or 242 Hz}$
So from the first condition, we get ${\nu }_x=258\text{Hz or 282 Hz}$
Thus frequency is 258 Hz.
Ans: B