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Standard XII

Physics

Thermal Resistance

Two rods of d...

Question

Two rods of different materials having different lengths and same cross sectional areas are joined end to end in a straight line. The free ends of this compound rod are maintained at different temperatures. The temperature gradient in each rod will be :

same

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zero

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directly proportional to thermal conductivity of rod

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inversely proportional to thermal conductivity of the rod

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Solution

The correct option is C inversely proportional to thermal conductivity of the rod
Thermal current across both rods will be same.
Now, thermal current = $\frac{K A}{L}$ x temperature gradient.
Since thermal current is same, temperature gradient $\propto$ $\frac{1}{K}$ .

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Two rods of different materials having different lengths and same cross sectional areas are joined end to end in a straight line. The free ends of this compound rod are maintained at different temperatures. The temperature gradient in each rod will be :

The correct option is C inversely proportional to thermal conductivity of the rodThermal current across both rods will be same.Now, thermal current = KAL x temperature gradient.Since thermal current is same, temperature gradient ∝ 1K.

The correct option is C inversely proportional to thermal conductivity of the rod
Thermal current across both rods will be same.
Now, thermal current = $\frac{K A}{L}$ x temperature gradient.
Since thermal current is same, temperature gradient $\propto$ $\frac{1}{K}$ .