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One end of a thermally insulated rod is kept at a temperature T_1 and the other at T_2. The rod is composed of two sections of lengths ell_1 and…

JEE Main 2007 — Physics Thermodynamics

2007mcqmedium

One end of a thermally insulated rod is kept at a temperature T1T_1T1​ and the other at T2T_2T2​. The rod is composed of two sections of lengths ℓ1\ell_1ℓ1​ and ℓ2\ell_2ℓ2​ and thermal conductivities k1k_1k1​ and k2k_2k2​ respectively. The temperature at the interface of the two sections is JEE Main 2007 Physics, Thermal Properties of Matter — question figure

Official previous-year question

Held on 30 Apr 2007 · Verified 6 Jul 2026.

Options

  1. A

    (k2ℓ2T1+k1ℓ1T2)/(k1ℓ1+k2ℓ2)\left(\mathrm{k}_2 \ell_2 \mathrm{T}_1+\mathrm{k}_1 \ell_1 \mathrm{T}_2\right) /\left(\mathrm{k}_1 \ell_1+\mathrm{k}_2 \ell_2\right)(k2​ℓ2​T1​+k1​ℓ1​T2​)/(k1​ℓ1​+k2​ℓ2​)

  2. B

    (k2ℓ1T1+k1ℓ1T2)/(k2ℓ1+k1ℓ2)\left(\mathrm{k}_2 \ell_1 \mathrm{T}_1+\mathrm{k}_1 \ell_1 \mathrm{T}_2\right) /\left(\mathrm{k}_2 \ell_1+\mathrm{k}_1 \ell_2\right)(k2​ℓ1​T1​+k1​ℓ1​T2​)/(k2​ℓ1​+k1​ℓ2​)

  3. C

    (k1ℓ2T1+k2ℓ1T2)/(k1ℓ2+k2ℓ1)\left(\mathrm{k}_1 \ell_2 \mathrm{T}_1+\mathrm{k}_2 \ell_1 \mathrm{T}_2\right) /\left(\mathrm{k}_1 \ell_2+\mathrm{k}_2 \ell_1\right)(k1​ℓ2​T1​+k2​ℓ1​T2​)/(k1​ℓ2​+k2​ℓ1​)

  4. D

    (k1ℓ1T1+k2ℓ2T2)/(k1ℓ1+k2ℓ2)\left(\mathrm{k}_1 \ell_1 \mathrm{T}_1+\mathrm{k}_2 \ell_2 \mathrm{T}_2\right) /\left(\mathrm{k}_1 \ell_1+\mathrm{k}_2 \ell_2\right)(k1​ℓ1​T1​+k2​ℓ2​T2​)/(k1​ℓ1​+k2​ℓ2​)

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