Question
Question: There are 26 tuning forks arranged in the decreasing order of their frequencies. Each tuning fork gi...
There are 26 tuning forks arranged in the decreasing order of their frequencies. Each tuning fork gives 3 beats with the next. The first one is octave of the last what is the frequency of 18thtuning fork?
A
100 Hz
B
99 Hz
C
96 Hz
D
103 Hz
Answer
99 Hz
Explanation
Solution
Let the frequency of first tuning fork is υ, The frequencies of other tuning forks are
(υ−3),(υ−2×3),.......(υ−17×3),.....(υ−25×3). As per given conditions,
υ=2(υ−25×3)orυ=2υ−25×6
Or υ=25×6=150Hz
The frequency of the 18thtuning fork
=υ−17×3=150−51=99Hz.