wave_mechanics critical_thinking Question 24

Question: Ten tuning forks are arranged in increasing order of frequency in such a way that any two nearest tuning forks produce 4 beats/sec. The highest frequency is twice of the lowest. Possible highest and the lowest frequencies are

[MP PMT 1990; MHCET 2002]

Options:

A) 80 and 40

B) 100 and 50

C) 44 and 22

D) 72 and 36

Show Answer

Answer:

Correct Answer: D

Solution:

Using nLast = nFirst + (N ? 1)x where N = Number of tuning fork in series x = beat frequency between two successive forks

Therefore 2n = n + (10 ? 1) ยด 4

Therefore n = 36 Hz \ nFirst = 36 Hz and nLast = 2 ยด nFirst = 72 Hz



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