Question

A black body radiates energy at the rate of W/m² at a high temperature TK. When the temperature is reduced to $\frac { T } { 2 } K$ , the radiant energy will be

• A. $\frac { E } { 16 }$
• B. $\frac { E } { 4 }$
• C.
• D. $16 E$

Answer 1

Answer: (A)

$\frac { E } { 16 }$

Answer 2

$E \propto T ^ { 4 } \Rightarrow \frac { E _ { 1 } } { E _ { 2 } } = \frac { T ^ { 4 } } { T ^ { 4 } } \times 2 ^ { 4 } \Rightarrow E _ { 2 } = \frac { E } { 16 }$