A solid at temperature T1 is kept in an evacuated chamber at temperature T2 > T1. The rate of increase of temperature of the body is proportional to
A. T2 – T1
B. T22 – T12
C. T23- T13
D. T24- T14
Stefan- Boltzmann Law is used.
According to the law, the energy of thermal radiation emitted per unit time by a body having surface area A is given as:
Here, e is the emissivity of the body and σ is the Stefan-Boltzmann constant and T is the Temperature.
As , temperature of solid will increase.
Now, for the solid the energy of thermal radiation is:
Energy of the thermal radiation in evacuated chamber is:
Now, the net difference in energy is .
Hence the net energy difference is proportional to:
Hence, The rate of increase of temperature of the body is proportional to .
For options (a), (b) and (c) the power od temperature difference is not 4. Hence, they are incorrect.
Thus, option (d) is the correct option.
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