An electric bulb with tungsten filament having an area of `0.25 cm^(2)` is raised to a temperature of `3000 K`, when a current passes through it. Calculate the electrical energy being consumed in watt, if the emissivity of the filament is 0.35. Stefan's constant, `sigma = 5.67 xx 10^(-5) erg^(-1) cm^(-2) K^(-4)`. If due to fall in main voltage the fialment temperature falls to 2500 K, what will be wattage of the bulb?

An electric bulb with a tungsten filament has an area of 0.20 cm^2 and is raised to a temperature of the bulb to 3000 K emissivity of the filament is 0.40 and Stefan's constant is 5.7 xx 10^(-5) erg s^(-1) cm^(-1) K^(-4) . The electrical energy consumed by the bulb is E_1 watt. If due to fall in voltage, the temperature of the filament falls to 2800 K, then the wattage of the bulb is E_2 watt. Calculate the value of E_1 - E_2 , close to nearest integer.

Calculate the temperature at which a perfect black body radiates at the rate of 1 W cm^(-2) , value of Stefan's constant, sigma = 5.67 xx 10^(-5) W m^(-2) K^(-8)

Calculate the temperature at which a perfect black body radiates at the rate of 1 W cm^(-2) , value of Stefan's constant, sigma = 5.67 xx 10^(-5) W m^(-2) K^(-8)

Calculate the temperature at which a perfect black body radiates at the rate of 1 W cm^(-2) , value of Stefan's constant, sigma = 5.67 xx 10^(-8) W m^(-2)K^(-4)

An electric bulb has a filameent of surface area 20" cm"^(2) . The filament is raised to a temperature of 1727^(0)C , when a current passes through it. If Stefan.s constant is 5.7xx10^(-8)W//m^(2)k^(4) and the emissivity of the filament is 0.5, the electric power being consumed to maintain this temperature is

An incandesent light bulb has a tungsten filament that is heated to a temperature 3 xx 106(3)K when an electric current passes through it If the surface area of the filament is approximately 10^(-4)m m^(2) and it has an emissivity of 0.3 the power radiated by the bulb is nearly (sigam = 5.67 xx 10^(-8) W m^(-2) K^(-4)) .

A metallic ball of surface area 300 cm^2 at a temperature of 227^@C is placed in a container at 27^@C . Calculate the rate of loss of heat radiation by the ball if emissivity of ball is 0.3, sigma = 5.67 xx 10^(-5) erg cm^(-2) s^(-1) K^(-4) .

A 10w electric bulb has tungsten filament of surface area 5 xx 10^(-5) m^2 . What is the temperature of the filament when incandescent ? Emissivity of the filament is 0.35 and Stefan's constant is 5.67 xx 10^(-8) Jm^(-2) s^(-1) k^(-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 )