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GATE 2020 ME (ME1) – Question 25

Heat Transfer · Convection: boundary layer, dimensionless parameters and correlations · 1 mark · Multiple choice

Match the non-dimensional numbers with the definitions. P: Reynolds; Q: Grashof; R: Nusselt; S: Prandtl. Definitions: 1: Buoyancy force / Viscous force; 2: Momentum diffusivity / Thermal diffusivity; 3: Inertia force / Viscous force; 4: Convective heat transfer / Conduction heat transfer.

  1. P–1, Q–3, R–2, S–4
  2. P–3, Q–1, R–2, S–4
  3. P–4, Q–3, R–1, S–2
  4. P–3, Q–1, R–4, S–2

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Show answer and explanation

Correct answer: (D) P–3, Q–1, R–4, S–2

Explanation

Reynolds compares inertia with viscous forces (3). Grashof compares buoyancy with viscous effects (1). Nusselt compares convection with conduction (4). Prandtl is momentum diffusivity divided by thermal diffusivity (2). **Answer: D.**