What is the net amount of energy per unit time being received by a body having a temperature of 40 °C in a surrounding of 60°C? (The surface area of body = 2m^2, σ = 5.67*10^-8W/ m^2K^4 & emissivity of 0.4).(a) 122.4W(b) 0.47W(c) 33W(d) 86W
Correct option is (a) 122.4WTo explain I would say: The body will receive some energy from the surrounding and also lose some to it.The net energy received will be= AeσT^4 – AeσTS^4= 2*0.4*5.67*10^-8(333^4 – 313^4)= 122.4 W.