Question 26: Waves

Question

Two open organ pipes A and B of length $$22 \mathrm{~cm}$$ and $$22.5 \mathrm{~cm}$$ respectively produce 2 beats per sec when sounded together. The frequency of the shorter pipe is

Accepted Answer

Frequency received by bat after reflection from wall-1,
$${f_1} = f\left[ {{{v + u} \over {v - u}}} ight] = 4.5 	imes {10^4}\left[ {{{330 + 6} \over {330 - 6}}} ight]$$
Given, $$f = 4.5 	imes {10^4}$$ Hz
$$ \Rightarrow {f_1} = 4.67 	imes {10^4}$$ Hz
Frequency received by bat after reflection from wall-2,
$${f_2} = f\left[ {{{v - u} \over {v + u}}} ight]$$
$$ = 4.5 	imes {10^4}\left[ {{{330 - 6} \over {300 + 6}}} ight]$$
$$ = 4.34 	imes {10^4}$$ Hz

Answer

92 Hz

Answer

90 Hz

Answer

88 Hz

Answer

86 Hz

Waves

Two open organ pipes A and B of length $22 \mathrm{~cm} and 22.5 \mathrm{~cm}$ respectively produce 2 beats per sec when sounded together. The frequency of the shorter pipe is

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