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Transmission of Heat — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsTransmission of Heat1 Mark
MCQ
Consider a compound slab consisting of two different materials having equal thickness and thermal conductivities $K$ and $2 K$ respectively. The equivalent thermal conductivity of the slab is
  • A
    $\sqrt{2 K}$
  • B
    $3 K$
  • ✓
    $\frac{4}{3} K$
  • D
    $\frac{2}{3} K$
✓

Answer

Correct option: C.
$\frac{4}{3} K$
(c) $\quad K=\frac{2 K_1 K_2}{K_1+K_2}=\frac{2 \cdot K \cdot 2 K}{K+2 K}=\frac{4}{3} K$

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