Question 32: Thermodynamics & KTG

Question

A black body radiates energy at the rate E Wm
$$-$$2
at high temperature TK. When the temperature is reduced to $$\left( {{T \over 4}} \right)$$ K, the new radiant energy is

Accepted Answer

Let E' be the new radiant energy.
According to Stefan's law,
E $$\propto$$ T
4
$$\Rightarrow$$ $${{{E_2}} \over {{E_1}}} = {\left( {{{{T_2}} \over {{T_1}}}} \right)^4}$$
$$\Rightarrow$$ $${{E'} \over E} = {\left\{ {{{(T/4)} \over T}} \right\}^4} = {\left( {{1 \over 4}} \right)^4}$$
or, $$E' = {E \over {256}}$$

Answer

$${E \over {256}}$$

Answer

4E

Answer

$${E \over {4}}$$

Answer

$${E \over {16}}$$

Thermodynamics & KTG

A black body radiates energy at the rate E Wm $-2 at high temperature TK. When the temperature is reduced to \left( {{T \over 4}} \right)$ K, the new radiant energy is

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