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))` .

An incandescent light bulb has a tungsten filament that is heated to a temperature 3xx10^(3)K when an electric current passes through it. If the surface area of the filament is approximately 10^(-4)m^(2) and it has an emissivity of 0.32, the power radiated by the bulb is

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?

The operating temperature of an in candescent bulb (with tungsten filament) of power 60 W is 3000 K. If the surface area of the filament be 25 mm^2 , find its emissivity e.

The operating temperature of an in candescent bulb (with tungsten filament) of power 60 W is 3000 K. If the surface area of the filament be 25 mm^2 , find its emissivity e.

How much energy in radiated per minute from the filament of an incandescent lamp at 3000 K, if the surface area is 10^(-4)m^(2) and its emissivity is 0.4 ? Stefan's constant sigma = 5.67 xx 10^(-8) Wm^(-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