A filament of an evacuated light blue has length 10 cm, diameter 0.2mm and emissivity 0.2. Calculate the power it radiates at 2000 K (`sigma=5.67xx10^-8 J/m^2k^4`)

A 100 watt filament loses all its power by radiation, when it is heated to a temperature 2500 K. If the diameter of the filament is 0.2mm and emissivity of the filament is 0.5, find the length of the filament to ( sigma = 5.67 xx 10^-8 J//m^2sK^4 )

Calculate the energy radiated in one minute by a black body of surface area 100 cm^2 when it is maintained at 227^@C ( sigma= 5.67 xx 10^-8 J/m^2sK^4 )

A 100 watt filament loses all its power by radiation when it is heated to a temperature of 2500 K. If the diameter of the filament is 0.2 mm and the surface emissivity of the filament is 0.5, find the length of the filament. (Stefan's constant sigma = 5.67 xx10^-8 W/m^2k^4 )

A metal cube has each side of length 1 m losses all its energy at a rate of 3000 watt. If the emissity is 0.4, Find its temperature (Given:a= 5.767xx10^-8J//m^2sk^-1 )

A copper sphere has a surface area of 3.142 xx 10^-2m^2 and its emissivity is 0.018. Find the energy lost by the sphere per second when its temperature is 100^@C . ( sigma = 5.67 xx 10^-8 W/m^2k^4 .)

Calculate the energy radiated is one minute by a blackbody of surface area 200 cm^2 at 127^@C ( sigma = 5.7 xx 10^-8 Jm^-2s^-1K^-4 )

Calculate the energy radiated in 30 seconds by perfectly black sphere of radius5cm maintained at 127^@C . (Stefan's constant s = 5.7 xx 10^-8 J//m^2sk^4)

A spherical black body of 5 cm radius is maintained at a temperature of 327^@C . Then the power radiated will be ( sigma = 5.7 xx 10^(-8) SI unit )

A body having a surface area of 50cm^2 radiates 300J of energy per minute at a temperature of 727^(@)C . The emissivity of the body is ( Stefan's constant =5.67xx10^(-8)W//m^2K^4 )