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The temperature θ at the junction of two insulating sheets, having thermal resistances R_1 and R_2 as well as top and bottom temperatures θ _1 and θ…

JEE Main 2021 — Physics Thermodynamics

2021mcqmedium

The temperature θ\thetaθ at the junction of two insulating sheets, having thermal resistances R1{R}_{1}R1​ and R2{R}_{2}R2​ as well as top and bottom temperatures θ1{\theta }_{1}θ1​ and θ2{\theta }_{2}θ2​ (as shown in figure) is given by :

JEE Main 2021 Physics, Thermal Properties of Matter — question figure

Official previous-year question

Held on 26 Feb 2021 · Verified 6 Jul 2026.

Options

  1. A

    θ1R2−θ2R1R2−R1\frac{{\theta }_{1}{R}_{2}-{\theta }_{2}{R}_{1}}{{R}_{2}-{R}_{1}}R2​−R1​θ1​R2​−θ2​R1​​

  2. B

    θ2R2−θ1R1R2−R1\frac{{\theta }_{2}{R}_{2}-{\theta }_{1}{R}_{1}}{{R}_{2}-{R}_{1}}R2​−R1​θ2​R2​−θ1​R1​​

  3. C

    θ1R2+θ2R1R1+R2\frac{{\theta }_{1}{R}_{2}+{\theta }_{2}{R}_{1}}{{R}_{1}+{R}_{2}}R1​+R2​θ1​R2​+θ2​R1​​

  4. D

    θ1R1+θ2R2R1+R2\frac{{\theta }_{1}{R}_{1}+{\theta }_{2}{R}_{2}}{{R}_{1}+{R}_{2}}R1​+R2​θ1​R1​+θ2​R2​​

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