Two strings X and Y of a sitar produce a beat frequency 4 Hz. When the tension of the string Y is slightly increased the beat frequency is found to be 2 Hz. If the frequency of X is 300 Hz, then the original frequency of Y was 

(1) 296 Hz

(2) 298 Hz

(3) 302 Hz

(4) 304 Hz

(1) nx=300Hz, ny=?

x = beat frequency = 4 Hz, which is decreasing (4 → 2)

after increasing the tension of the string y.

Also tension of wire y increasing so ny (nT)

Hence nxny=x → Correct

nynx=x → Wrong

ny=nxx=3004=296Hz

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