Question

Suppose you have a box one meter cach direction. The temperature of the box is 300K. What is the luminosity? ( Watt of the box is sooer long in cach direction. There are 6 sides to the box). A. 220 Watts B. 275 Watts C. 2750 Watts D. 22,000 Watts E. 39,500 Watts

Answer 1

Answer:

C. 2750 Watts

Explanation:

Length of the each side of the box is,

$a=1m$

Total surface area of the box,

$SA=6a^{2}\\ SA=6m^{2}$

And the temperature of the box is,

$T=300 K$

From the Stefan Boltzmann law 1 square meter will emit light is,

$\sigma T^{4}$

$\sigma$ is the Stefan constant of value,$\sigma=5.67\times 10^{-8}Wm^{-1}$

Therefore luminosity is,

$L=\sigma T^{4}\times SA$

Therefore

$L= 5.67\times 10^{-8}Wm^{-1}\times (300)^{4}\times 6\\L=2755.62 Watts$

Therefore, the luminosity is 2755.62 watt which is quite close to 2750 Watts which is given in options.