An electric heater emits 100W of thermal radiation. The coil has a surface area of `0.02m^(2)` . Assuming that the coil radiates like a blackbody, Find its temperature. Sigma=6.00xx10^(-s)Wm^(-2)K(-4)` .

An electric heater emits 1000W of thermal radiation. The coil has a surface area of 0.02m^(2) . Assuming that the coil radiates like a blackbody, Find its temperature. sigma=6.0xx10^(-8)Wm^(-2)K^(-2) .

An electric heater emits 1000W of thermal radiation. The coil has a surface area of 0.02m^(2) . Assuming that the coil radiates like a blackbody, Find its temperature. sigma=6.0xx10^(-8)Wm^(-2)K^(-2) .

An electric heater ofpower 1kW emits thermal radiations the surface area of heating element of heater is 200 cm^(2) . If this heating element is treated like a black bodyfind the temperature at its surface. Assume its temperature is very much higher then its surroundings.

Calculate the saturation thermionic current if 120 W is applied to a thoriated-tungsten filament of surface area 1.0 cm^2 . Assume that the surface radiates like a blackbody. The required constants are A = 3 xx10^4 A m^(-2) -K^2 , varphi = 2.6 eV, k = 8.62 xx 10^(-5) eV kK^(-1) and sigma = 6 xx 10^(-8) W m^(-2) K^(-4)

Calculate the saturation thermionic current if 120 W is applied to a thoriated-tungsten filament of surface area 1.0 cm^2 . Assume that the surface radiates like a blackbody. The required constants are A = 3 xx10^4 A m^(-2) -K^2 , varphi = 2.6 eV, k = 8.62 xx 10^(-5) eV kK^(-1) and sigma = 6 xx 10^(-8) W m^(-2) K^(-4)

Calculate the amount of radiation of a black body at 400K temperature. (sigma= 5.67 xx 10^-8 watt//m^2 //k^4)

A hot water radiator at 310 K temperature radiates thermal radiation like a black body. Its total surface area is 1.6m^(2). Find the thermal power radiated by it.

The constant A in the Richardson-Dushman equation for tungsten is 60 xx 10^(4) A m^(-2) . The work function of tungsten is 4.5 eV . A tungsten cathode having a surface area 2.0 xx 10^(-5) m^2 is heated by a 24 W electric heater. In steady state, the heat radiated by the cathode equals the energy input by the heater and the temperature becomes constant. Assuming that the cathode radiates like a blackbody, calculate the saturation current due to thermions. Take Stefan constant = 6 xx 10^(-8) W m^(-2) K^(-4) . Assume that the thermions take only a small fraction of the heat supplied.

The constant A in the Richardson-Dushman equation for tungsten is 60 xx 10^(4) A m^(-2) . The work function of tungsten is 4.5 eV . A tungsten cathode having a surface area 2.0 xx 10^(-5) m^2 is heated by a 24 W electric heater. In steady state, the heat radiated by the cathode equals the energy input by the heater and the temperature becomes constant. Assuming that the cathode radiates like a blackbody, calculate the saturation current due to thermions. Take Stefan constant = 6 xx 10^(-8) W m^(-2) K^(-4) . Assume that the thermions take only a small fraction of the heat supplied.

Calculate the amount of heat radiated per second by a body of surface area 12cm^(2) kept in thermal equilibrium in a room at temperature 20^(@)C The emissivity of the surface =0.80 and sigma=6.0xx10^(-s)Wm^(-2)K^(-4) .