An electric heater kept in a vacuum is heated | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

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:

Similar Questions

$A$ rectangular metal plate $8 \ cm \times 4 \ cm$ at $127^{\circ} C$ emits $E \ Js^{-1}$. If both length and breadth are halved and the temperature is raised to $327^{\circ} C$,the rate of emission is

What will be the ratio of the rate of radiation of a metal sphere at two different temperatures $T_1 = 527^\circ C$ and $T_2 = 127^\circ C$ (in $:$)?

The spectrum of a black body at two temperatures $27\,^oC$ and $327\,^oC$ is shown in the figure. Let $A_1$ and $A_2$ be the areas under the two curves respectively. Find the value of $\frac {A_2}{A_1}$.

The distance between the Sun and the Earth is $2 \times 10^{8} \ km$, the temperature of the Sun is $6000 \ K$, and the radius of the Sun is $7 \times 10^{5} \ km$. If the emissivity of the Earth is $0.6$, find the temperature of the Earth in thermal equilibrium (in $K$).

$A$ tungsten body of diameter $2.3 \ cm$ is at $2000 \ ^oC$. It radiates $30 \%$ of the energy radiated by a black body of the same radius and temperature. Find the radius of a black body which will radiate energy at the same rate at the same temperature (in $cm$).

Vedclass Test Series

Exam Paper Generator

Online Exam Module