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JEE Main20203 Sep 2020Morning ShiftPhysicsWaves and SoundActual

A uniform thin rope of length 12 m and mass 6 kg hangs vertically from a rigid support and a block of mass 2 kg is attached to its free end. A transverse short wave train of wavelength 6 cm is produced at the lower and the rope. What is the wavelength of the wave train (in cm ) when it reaches the top of the rope?

Options

  1. A3
  2. B6
  3. C12
  4. D9

Correct answer

C. 12

Step-by-step solution

V = fλ V 1 λ 1 = V 2 λ 2 λ 2 = V 2 V 1 λ 1 = T 2 T 1 λ 1 T 2 = 8 g Top 8 g 2 g λ 1 T 1 = 2 g Bottom = 2 λ 1 = 12 cm

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