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MHT CET202415 May 2024Morning ShiftPhysicsWaves and SoundActual

The driver of a car travelling with a speed ' V ₁ ' m / s towards a wall sounds a siren of frequency ' n ' Hz. If the velocity of sound in air is Vm / s , then the frequency of sound reflected from the wall and as heard by the driver, in Hz , is

Options

  1. A( V+V₁ V-V₁ ) n
  2. B( V - V ₁ ~V + V ₁ ) n
  3. C( V₁-V V₁+V ) n
  4. D( V₁ V₁-V ) n

Correct answer

A. ( V+V₁ V-V₁ ) n

Step-by-step solution

As source of sound (reflected sound) and the listener (car driver) are both moving towards each other, n^ =n ( V+V_l V-V_s ) Here V _ l = V _ s = V ₁ n ^ = n ( ~V + V ₁ ~V - V ₁ )

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