A second harmonic has to be generated in a string of length l stretched between two rigid supports.

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14.Waves and Sound

easy

A second harmonic has to be generated in a string of length $l$ stretched between two rigid supports. The points where the string has to be plucked and touched are respectively

$\frac{l}{4}, \frac{l}{2}$

$\frac{l}{4}, \frac{3l}{4}$

$\frac{l}{2}, \frac{l}{2}$

$\frac{l}{2}, \frac{3l}{4}$

Solution

(a)

In the $2^{\text {nd }}$ harmonic the shape of wave looks like.

The point of touching forms a node point of plucking forms an antinode. Hence, for $2^{\text {nd }}$ harmonic, we need to need wire touched at $\frac{l}{2}$ and pluck it at $\frac{l}{4}$.

Standard 11

Physics

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medium

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normal

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hard

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