The surface area of a black body is `5xx10^(-4) m^(2)` and its temperature is `727^@C` . Energy radiated by it per minute is (Take `sigma =5.67xx10^(-8) "J m"^(-2) s^(-1) K^(-4)` )

A body which has a surface area 5.00 cm^(2) and a temperature of 727^(@)C radiated 300 j of energy each minute. What is the emissivity of body? Steafan's constant =5.67xx10^(-8) Wm^(-2) K^(-4) .

Calculate the energy radiation by the sun in 2 mins if it is considered to be perfect sphere of radius 6.8 xx 10^8 m and its surface temperature is approximately 6200 K. Take sigma = 5.67 xx 10^(-8) Jm^(-2) s^(-1) K^(-4)

A cube, which may be regarded as a perfectly black body, radiates heat at the rate of 2770.2 watt when its temperature is 27^(@)C . The volume of the cube is (sigma=5.7xx10^(8)J//m^(2)" s "K^(4))

A body which has surface area of 5.0 cm^2 and a temperature of 727 radiates 300j of energy per minute.What is its emissivity?( sigma=5.67*10^-8 W/m^-2 K^-4 )

A very small hole in an electric furnance is used for heating metals . The hole nearly acts as a black body . The area of the hole is 200 mm^(2) . To keep a metal at 727^@C , heat energy flowing through this hole per sec, in joules is ( sigma= 5.67 xx 10^(-8)Wm^(-2)K^(-4) )

The power of a black body at temperature 200K is 544 watt. Its surface area is (sigma = 5.67 xx 10^(-8) wm^(-2) K^(-4))