Two sound waves move in the same direction in the same medium. The pressure amplitudes of the waves are equal but the wavelength of the first wave is double the second. Let the average power transmitted across a cross section by the first wave be P 1 and that by the second wave be P 2 . Then

Question

Philoid · Accepted Answer

Let the cross-section area = A, if the intensity of the first wave at this cross-section = I₁ and of the second wave = I₂, then
P₁ =AI₁ and P₂ = AI₂.
But the intensity

Since for a given medium velocity of sound V and the bulk modulus B are constant, I depend only on the pressure amplitude p₀. Since in the given problem pressure amplitude of both waves are same hence I₁ = I₂
→P₁ = P₂
So the option A is correct.

Two sound waves move in the same direction in the same medium. The pressure amplitudes of the waves are equal but the wavelength of the first wave is double the second. Let the average power transmitted across a cross section by the first wave be P1 and that by the second wave be P2. Then

Two sound waves move in the same direction in the same medium. The pressure amplitudes of the waves are equal but the wavelength of the first wave is double the second. Let the average power transmitted across a cross section by the first wave be P₁ and that by the second wave be P₂. Then