Home
Class 12
PHYSICS
A 500W lamp loses all of its energy by e...

A 500W lamp loses all of its energy by emission of radiation from the surface. If the area of the surface of the filament is `2.0cm^(2)` and its emissivity is 0.5, estimate the temperature of its filameiit. Given that Stefan constant, ` sigma =5.7xx10^(-8)W//m^(2)K^(4).` Neglect radiation receivedby lamp from surrounding.

Text Solution

AI Generated Solution

To solve the problem, we will use Stefan-Boltzmann's law, which states that the power radiated by a black body is proportional to the fourth power of its absolute temperature. The formula is given by: \[ P = \sigma \cdot \epsilon \cdot A \cdot T^4 \] Where: - \( P \) = Power radiated (W) - \( \sigma \) = Stefan-Boltzmann constant (\( 5.7 \times 10^{-8} \, \text{W/m}^2\text{K}^4 \)) - \( \epsilon \) = Emissivity of the surface (dimensionless) ...
Promotional Banner

Topper's Solved these Questions

  • HEAT TRANSFER

    PHYSICS GALAXY - ASHISH ARORA|Exercise Practice Exercise 4.3|5 Videos

  • HEAT TRANSFER

    PHYSICS GALAXY - ASHISH ARORA|Exercise Practice Exercise 4.4|5 Videos

  • HEAT TRANSFER

    PHYSICS GALAXY - ASHISH ARORA|Exercise Practice Exercise 4.1|11 Videos

  • HEAT AND THERMAL EXPANSION

    PHYSICS GALAXY - ASHISH ARORA|Exercise UNSOLVED NUMRICAL PROBLEMS FOR PREPARATION OF NSEP, INPhO & IPhO|82 Videos

  • Kinetic Theory of Gases and Gas Laws

    PHYSICS GALAXY - ASHISH ARORA|Exercise Unsolved Numerical Problems for Preparation of NSEP, INPhO & IPhO|64 Videos

Similar Questions

Explore conceptually related problems

A 300 W lamp loses all its energy by emission of radiation from the surface of its filament. If the area of surface of filament is 2.4cm^(2) and is of emissivity 0.4, estimate its temperature. Given that sigma = 1.36 xx 10^(-12) cal cm^(-2) s^(-1) K^(-4) J=4.2 J cal^(-1) . Neglect the absorption from the surroundings.

Assume that a 100W electric bulb loses its energy entirely by radiation from the surface of its filament . If the surface area of the filament is 2 cm^(2) and its coefficient of emission is 0.4 , calculate the temperature of the filament.

The operating temperature of a tungesten filament in an indandescent lamp is 2000 K and its emissivity is 0.3 . Find the surface area of the filament of a 25 watt lamp. Stefan's constant sigma = 5.67xx10^(-8) Wm^(-2)K^(-4)

The tungsten filamet of an electric lamp, has a length of 0.25 m and a diameter of 6xx10^(-5) m. The power rating of the filament is 0.8, estimate the steady temperature of filament. Stefan's constant =5.67xx10^(-8) W//m^(-2)//K^(4) .

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) .

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 )

The surface of a black body is at a tempera ture 727^(@)C and its cross section is 1m^(2) Heat radi ated from this surface in one minute in Joules is (Stefan's constant =5.7 xx 10^(-8) W//m^(2)//k^(4)) .

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)

The power of black body at temperature 200 K is 544 W .Its surface area is (sigma=5.67xx10^(-8)Wm^(-2)K^(-2))

If the sun's surface radiates heat at 6.3 xx 10^(7) Wm^(-2) . Calculate the temperature of the sun assuming it to be a black body (sigma = 5.7 xx 10^(-8)Wm^(-2)K^(-4))