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Five beats per second are heard when a tuning fork is sounded with a sonometer wire under tension, for a wire length of either 0.95 m or 1 m. The frequency of the fork is

Asked in JEE Main Online 2018 · Unknown fork frequency and tuning

Answer: (3) 195 Hz

Step-by-step solution

For a fixed tension f∝1/L. Let the 1 m wire sound at f₀; then the 0.95 m wire sounds at (f₀)/(0.95).

The fork lies between them: f₀+5=(f₀)/(0.95)-5.

10=f₀(1/(0.95)-1)=0.0526f₀, so f₀=190 Hz and the fork is at 190+5=195 Hz.

Why the other options are wrong

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