An electric heater kept in a vacuum is heated | vedclass

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Question

(D) In a vacuum, there is no medium for heat transfer via conduction or convection. The electric heater generates heat at a constant rate $P = I^2R$.

Vedclass · Accepted Answer

Will become constant after sometime because of loss of heat due to radiation

Vedclass · Answer

(D) In a vacuum, there is no medium for heat transfer via conduction or convection. The electric heater generates heat at a constant rate $P = I^2R$. As the temperature of the heater increases, it loses heat to the surroundings through electromagnetic radiation, following the Stefan-Boltzmann law $(P_{rad} = \sigma A \epsilon T^4)$. Initially, the rate of heat generation is greater than the rate of heat loss. As the temperature rises, the rate of heat loss increases until it equals the rate of heat generation. At this point, the heater reaches thermal equilibrium, and its temperature becomes constant.

An electric heater kept in a vacuum is heated continuously by passing an electric current. Its temperature:

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