wave_mechanics critical_thinking Question 27
25 tuning forks are arranged in series in the order of decreasing frequency. Any two successive forks produce 3 beats/sec. If the frequency of the first tuning fork is the octave of the last fork, then the frequency of the 21st fork is
[Kerala (Engg.) 2001]
Options:
A) 72 Hz
B) 288 Hz
C) 84 Hz
D) 87 Hz
Show Answer
Answer:
Correct Answer: C
Solution:
According to the question frequencies of first and last tuning forks are n and 2n respectively.
Hence frequency in the given arrangement are as follows
Therefore 2n ? 24 × 3 = n
Therefore n= 72 Hz So, frequency of 21st tuning fork $ n _{21}=(2\times 72-20\times 3)=84Hz $
BETA
