MHT CET Medical202624 April 2026Evening ShiftPhysicsWaves and SoundActual
Two sources of sound placed closed to each other, are emitting progressive waves given by y₁ = 4 (600 t) and y₂ = 5 (608 t) . An observer located near these two sources of sound will hear
Options
- A4 beats/s with intensity ratio 25 : 16 between waxing and waning.
- B8 beats/s with intensity ratio 25 : 16 between waxing and waning.
- C8 beats/s with intensity ratio 81 : 1 between waxing and waning.
- D4 beats/s with intensity ratio 81 : 1 between waxing and waning.
Correct answer
D. 4 beats/s with intensity ratio 81 : 1 between waxing and waning.
Step-by-step solution
The given equations of the progressive waves are: y₁ = 4 (600 t) y₂ = 5 (608 t) Comparing these with the standard equation y = A ( t) , we get the angular frequencies: ₁ = 600 2 f₁ = 600 f₁ = 300 Hz ₂ = 608 2 f₂ = 608 f₂ = 304 Hz The beat frequency is the difference between the frequencies of the two waves: n = |f₁ - f₂| = |300 - 304| = 4 beats/s The amplitudes of the two waves are A₁ = 4 and A₂ = 5 . The maximum amplitude during waxing is A_ max = A₁ + A₂ = 4 + 5 = 9 . The minimum amplitude during waning is A_ min