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MHT CET 2025 (19 Apr, Shift 2) · Viscosity & Stokes' Law

Viscosity & Stokes' Law question from MHT CET 2025 (19 Apr, Shift 2)

Q5MHT CET 2025 · 19 APR · SHIFT 2Medium

Viscosity & Stokes' Law

Water is flowing steadily in a river. A and B are the two layers of water at heights 40 cm and 90 cm from the bottom. The velocity of the layer A is 12 cm/s12\text{ cm/s}. The velocity of the layer B is

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Answer: (c)

  1. In steady flow the velocity gradient is uniform and the bottom layer is at rest, so v∝hv \propto h.
  2. vBvA=9040⇒vB=12×94\frac{v_B}{v_A} = \frac{90}{40} \Rightarrow v_B = 12\times\frac{9}{4}
  3. vB=27v_B = 27 cm/s
  4. So the answer is (c) 2727 cm/s.
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