Q. Tuning fork $F_{1}$ has a frequency of $256\ Hz$ and it is observed to produce 6 beats/second with another tuning fork $F_{2}.$ When $F_{2}$ is loaded with wax, it still produces 6 beats/second with $F_{1}.$ The frequency of $F_{2}$ before loading was
A) $253\ Hz$
B) $262\ Hz$
C) $250\ Hz$
D) $259\ Hz$
Explanation
(b) $n_{A} =$ Known frequency $= 256\ Hz,\ n_{B} = ?$
$x = 6\ bps,$ which remains the same after loading.
Unknown tuning fork $F_{2}$ is loaded so $n_{B} \downarrow$
Hence $n_{A} - n_{B} \downarrow = x\ \ \rightarrow$ Wrong …(i)
$n_{B} \downarrow - n_{A} = x\ \ \rightarrow$ …(ii)
$\Rightarrow n_{B} = n_{A} + x = 256 + 6 = 262\ Hz$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.