Question

An unknown frequency $x$ produces $8$ beats per seconds with a frequency of $250Hz$ and $12$ beats with $270Hz$ source, then $x$ is

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

Answer 1

Answer: (A)

Since source of frequency $x$ gives 8 beats per second with frequency $250Hz$, its possible frequency are 258 or $242.$ As source of frequency $x$ gives 12 beats per second with a frequency $270Hz$, its possible frequencies 282 or $258Hz$. The only possible frequency of $x$ which gives 8 beats with frequency $250Hz$ also 12 beats per second with $258Hz$.