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JEE Main20205 Sep 2020Morning ShiftPhysicsWaves and SoundActual

Assume that the displacement (s) of air is proportional to the pressure difference Δ p created by a sound wave. Displacement (s) further depends on the speed of sound (v), density of air ρ and the frequency (f). If Δ p ~ 10 P a , n ~ 300 m / s , p ~ 1 k g / m 3 f ~ 1000 H z , then s will be of the order of (take the multiplicative constant to be 1 )

Options

  1. A3 100 mm
  2. B10   mm
  3. C1 10 mm
  4. D1   mm

Correct answer

A. 3 100 mm

Step-by-step solution

S = P 0 B K = P 0 P V 2 ω V = P 0 P V ω = 10 1 × 1000 × 300 m ≃ 3 100 mm

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