Tag: beats in sound waves

Questions Related to beats in sound waves

If 2 waves of same frequency and same amplitude on superposition, produce a resultant disturbance of the same amplitude, the waves differ in phase by

physics superposition of waves-1: interference and beats distinction between interference and beats beats and its applications beats in sound waves

  1. $ \dfrac { \pi }{ 3 } $

  2. $ \dfrac { 2\pi }{ 3 } $

  3. $ { \pi } $

  4. $ { 3\pi } $

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Correct Option: B
Explanation:

Let the amplitude of each wave be $A$ i.e.  $A _1 = A _2 = A$
Thus amplitude of resultant wave  $A _R =A$
Using   $A^2 _R =  A _1^2 + A _2^2 + 2A _1A _2 \cos\theta$
$\therefore$  $A^2 =  A^2 + A^2 + 2A^2 \cos\theta$
Or  $\cos\theta = -0.5$
$\implies  \ \theta = \dfrac{2\pi}{3}$

Two identical wires are stretched by the same tension of $101$ N & each emits a note of frequency $202$ Hz. If the tension in one wire is increased by $1N$ , then the beat frequency is:

physics superposition of waves-1: interference and beats distinction between interference and beats beats and its applications beats in sound waves

  1. $2 Hz$

  2. $\frac{1}{2}Hz$

  3. $1 Hz$

  4. None of these

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Correct Option: C