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Question
N tuning forks are arranged in order of increasing frequency and any two successive tuning forks give n beats per second when sounded together. If the last fork gives double the frequency of the first (called as octave), Show that the frequency of the first tuning fork is f = (N – 1)n.
Solution
Total number of fork = N
The frequency of the 1st fork = f
The frequency of the last fork = 2f
∴ an = a + (n – 1)d
2f = f + (N – 1)n
2f – f = (N – 1)n
∴ f = (N – 1)n
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