Q 11-14-021NEETJEE MainTop questionEasy
A tuning fork of frequency $256$ Hz produces $4$ beats per second with another fork. When the second fork is loaded with a little wax, the beat frequency decreases. The original frequency of the second fork was
Answer: (A) $260$ Hz
Concept. Beat frequency $= |f_1 - f_2|$. Wax lowers the second fork's frequency; see which choice makes the beats decrease.
Step 1. Possible values. $256 \pm 4 = 252$ or $260$ Hz.
Step 2. Test. Lowering $252$ Hz would increase the beats; lowering $260$ Hz brings it closer to $256$ and decreases them. ✓
Answer. $260$ Hz (Option A).
Solution by Sreeraj P, M.Sc Physics