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NEET2005PhysicsThermal Properties of MatterActual

Which of the following rods, (given radius r and length l ) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?

Options

  1. Ar=r₀ l=l₀
  2. Br=2 r₀ l=l₀
  3. Cr=r₀ l=2 l₀
  4. Dr=2 r₀ l=2 l₀

Correct answer

B. r=2 r₀ l=l₀

Step-by-step solution

Heat conducted = K A (T₁-T₂ ) t l = K r^2 (T₁-T₂ ) t l The rod with maximum ratio of A l will conduct most. Here the rod r=2 r₀ and l=l₀ will conduct most.

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