wave_mechanics Beats Question 12
Question: 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
[MP PET 1990]
Options:
A) 253 Hz
B) 262 Hz
C) 250 Hz
D) 259 Hz
Show Answer
Answer:
Correct Answer: B
Solution:
nA = Known frequency = 256 Hz, nB = ? x = 6 bps, which remains the same after loading.
Unknown tuning fork F2 is loaded so nB¯ Hence nA ? nB¯ = x …
(i) Wrong nB¯ ? nA = x …
(ii) Correct
Therefore nB = nA + x = 256 + 6 = 262 Hz.