When two waves with same frequency and constant phase difference interfere,
(a) there is a gain of energy
(b) there is a loss of energy
(c) the energy is redistributed and the distribution changes with time
(d) the energy is redistributed and the distribution remains constant in time.
(d) the energy is redistributed and the distribution remains constant in time.
EXPLANATION:
The energy at a point due to the sound wave is proportional to the square of the pressure amplitude. When two waves with the same frequency and constant phase difference interfere, the energy is redistributed because the resultant pressure amplitude p₀ is given by p₀² = p₀₁² + p₀₂² + 2p₀₁ p₀₂ cosδ here p₀₁ and p₀₂ are pressure amplitudes of the two waves and δ is the phase difference. Since δ is constant here, so p₀ remains constant in time. Thus the energy redistribution remains constant in time. So the option (d).