Question

A circular grill of diameter 0.25 m has an emissivity of 0.8. If the surface temperature is maintained at 150°C, determine the required electrical power when the room air and surroundings are at 30°C.

Answer 1

the required electrical power when the room air and surroundings are at 30°C.= 52.51822 Watt

Step-by-step explanation:

Power required to maintain the surface temperature at 150°C from 20°C

P= εσA(T^4-t^4)

P= power in watt

ε= emissivity

A= area of surface

T= 150°C= 423 K

t= 20°C= 303K

/sigma= 5.67×10^{-8} watt/m^2K^4

putting vales we get

`= 0.8*5.67*10^(-8) \pi(0.25^4)/(4)(423^4-303^4)`

P=52.51822 Watt

the required electrical power when the room air and surroundings are at 30°C.= 52.51822 Watt