A thin square steel plate 10 cm on a side is heated in a black smith's forge to temperature of `800^@C`. If the emissivity is 0.60, what is the total rate of radiation of energy ?

A copper ball 2 cm in radius is heated in a furnace at 327^@C If its emissivity is 0.3, at what rate does it radiate energy ?

A thin square steel plate with each side equal to 10 cm is heated by a blacksmith. The rate of radiated energy by the heated plate is 1134 W . The temperature of the hot steel plate is (Stefan's constant sigma = 5.67 xx10^(-8) " watt "m^(-2) K^(-4) , emissivity of the plate = 1)

The temperature of the sun is 6000 K and is treated as a black body. The solar heat energy radiated by the sun is 10^(9)W//m^(2) . What is the temperature of a black body if it radiated heat energy of 10^(5)W//m^(2) ?

If the temperatures of a black body increases from 7^@ C to 287^@ C then, the rate of energy of radiation is

The temperature of a black body increases from 7°C to 287°C .The rate of energy radiation increases by

A steel plate is 0.3 m long, 0.1m wide and 0.012 m thick. The plate is placed on a heating plate of identical size maintained at 100^(@)C . The heating plate is receiving energy through a 50 W heater. The heating plate losses heat only to the steel plate which is well insulated from all sides except at the top. The top surface of the steel plate is exposed to an airstream of temperature 20^(@)C . The top surface of the steel plate radiates like a black body. Calculate the rate at which the top surface looses heat due to convection. The surface of steel plate in contact with heating plate is at 100^(@)C . Thermal conductivity of steel k = 16 Wm^(-1)K^(-1) Stefan’s constant =5.67xx10^(-8)Wm^(-2)K^(-4)

The rate of dissipation of heat by a black body at temperature T is Q . What will be the the rate of dissipation of heat by another body at temperature 2T and emissivity 0.25 ?