The tungsten filament of an electric lamp has a surface area A and a power rating P- If the emissivity of the filament is - and - is Stefan-s constant- the steady temperature of the filament will beA- T-p-A -2B- T-p-pp-1-2C - T-p2-A -D- T-p-A -1-4

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Physics

Stefan-Boltzman's Law

The tungsten ...

Question

The tungsten filament of an electric lamp has a surface area A and a power rating P. If the emissivity of the filament is $ϵ$ and $σ$ is Stefan’s constant, the steady temperature of the filament will be

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D

The energy radiated per second per unit area at temperature T is given

$= σ ϵ T^{4}$

Thus, the energy radiated per second (or power radiated) from the filament of area A is

$p = A σ ϵ T^{4} O r T = {(\frac{p}{A σ ϵ})}^{\frac{1}{4}}$

Hence the correct choice is (d)

Suggest Corrections

Similar questions

The tungsten filament of an electric lamp has a surface area A and a power rating P. If the emissivity of the filament is $ϵ$ and $σ$ is Stefan's constant, the steady temperature of the filament will be

Q. The tungsten filament of an electric lamp has a length of

0.5 m

and a diameter

6 \times 10^{- 5} m

. The power rating of the lamp is

60 W

. Assuming the radiation from the filament is equivalent to 80% of a perfect black body radiator at the same temperature, estimate the steady state temperature of the filament (Stefan's constant

= 5.7 \times 10^{- 8} {W m}^{- 2} K^{- 4}

)

Q. The operating temperature of a tungsten filament in an incandescent lamp is

2000 K

and its emissivity is

0.3

. Find the surface area of the filament of a

25 watt

lamp.
Stefen's constant

σ = 5.67 \times 10^{- 8} {W m}^{- 2} K^{- 4}

Q. A tungsten filament lamp of power

625

watt is at 2227

^{o}

C. The emissivity of the filament is

0.16

. If

σ =

6 \times 10

^{- 8}

^{- 2}

^{- 4}

, the surface area of the filament is nearly :

Q. 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

σ = 5.67 \times 10^{- 8} W / m^{2} K^{4}

]

Join BYJU'S Learning Program

The tungsten filament of an electric lamp has a surface area A and a power rating P. If the emissivity of the filament is ϵ and σ is Stefan’s constant, the steady temperature of the filament will be

The correct option is D The energy radiated per second per unit area at temperature T is given =σϵT4 Thus, the energy radiated per second (or power radiated) from the filament of area A is p=A σϵT4Or T=(pAσϵ)14 Hence the correct choice is (d)

The tungsten filament of an electric lamp has a surface area A and a power rating P. If the emissivity of the filament is $ϵ$ and $σ$ is Stefan’s constant, the steady temperature of the filament will be

The correct option is D

The energy radiated per second per unit area at temperature T is given

$= σ ϵ T^{4}$

Thus, the energy radiated per second (or power radiated) from the filament of area A is

$p = A σ ϵ T^{4} O r T = {(\frac{p}{A σ ϵ})}^{\frac{1}{4}}$

Hence the correct choice is (d)