Q 11-14-072JEE MainJEE Main 2022 (26 Jun, Shift 2)Easy
A set of $20$ tuning forks is arranged in a series of increasing frequencies. If each fork gives $4$ beats with respect to the preceding fork and the frequency of the last fork is twice the frequency of the first, then the frequency of the last fork is ______ Hz.
Numerical value type. Enter your answer.
Answer: 152
$f_{20} = f_1 + 19\times4 = f_1 + 76$ and $f_{20} = 2f_1$, so $f_1 = 76\ \text{Hz}$ and $f_{20} = 152\ \text{Hz}$.
Solution by Sreeraj P, M.Sc Physics