Question

A source x of unknown frequency produces 8 beats with a source of 250 Hz and 12 beats with a source of 270 Hz. The frequency of source x is

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

Answer 1

The correct option is A 258 Hz

$Beats={\delta }_1-{\delta }_2$
In case I:
So, $8=250-xor8=x-250$
$\Rightarrow x=242$ $\Rightarrow x=258$
In case II:
$12=270-xor8=x-250$
$\Rightarrow x=258$ $\Rightarrow x=282$

As $x=258$ is applicable to both case I and case II
So, $x=258H_z$