Question

The effective area of black body is 0.1 m^2 and it's temperature is 1000k . The amount of radiations emitted by it per min. Is ?

Answer 1

81 k-cal

the formula is:

dQ/dT=AσT⁴(watts)

Answer 2

The energy radiated per minute is 5.670 KJ.

Solution:

Given that,

Temperature T = 1000 K

Surface area, A = 0.1 $m^2$

Relative emittance, e = 1 (it varies from 0 to 1) Taken as 1.

Using Stefan's law of radiation,

The total heat energy emitted from a surface is proportional to the fourth power of temperature.

Formula for the energy radiated is, E = $e \sigma T^4 A$

Where, $\sigma$ is the Stefan's constant = 5.67 $\times$ $10^{-8}$ $W m^{-2} K^{-4}$

Then, substitute the values,

                                                 E = 1 $\times$ 5.67 $\times$ $10^{-8}$ $\times 1000^4 \times 0.1$

                                              = 5.670 KJ

Hence, the energy radiated per minute is 5.670 KJ

To know more:

Calculate the energy radiated per minute from the filament of an incandascent lamp at 2000k if the surface area is 5 m2 and its relative emittance is 0.85

https://brainly.in/question/8006608