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GATE 2026 ME – Question 27

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

A quiescent fluid at temperature $T_3$ is confined between two vertical parallel plates. While plate 1 is kept at temperature $T_1$ and plate 2 is maintained at temperature $T_2$, a velocity profile between the plates, as shown in the figure below, is generated due to heat transfer. Which one of the following options shows the correct relations among $T_1$, $T_2$, and $T_3$?

Two vertical plates, plate 1 on the left at temperature $T_1$ and plate 2 on the right at temperature $T_2$, with gravity pointing down. The velocity profile shows upward flow near plate 1 and downward flow near plate 2.
  1. $T_1 > T_3$ and $T_3 > T_2$
  2. $T_1 > T_3$ and $T_3 < T_2$
  3. $T_1 < T_3$ and $T_3 < T_2$
  4. $T_1 < T_3$ and $T_3 > T_2$

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Show answer and explanation

Correct answer: (A) $T_1 > T_3$ and $T_3 > T_2$

Explanation

Fluid that is heated becomes lighter and rises, and fluid that is cooled becomes heavier and sinks. The fluid rises next to plate 1, so plate 1 is hotter than the fluid, $T_1 > T_3$. The fluid sinks next to plate 2, so plate 2 is colder than the fluid, $T_2 < T_3$.