Calculate the energy radiated per minute from the filament of an incandescent lamp at 2000 K. If the surface area is 5 × 10-5 m 2 and its relative emittance is 0.85, σ=5.7 × 10-8 MKS units

Question

Calculate the energy radiated per minute from the filament of an incandescent lamp at 2000 K. If the surface area is 5 × 10-5 m 2 and its relative emittance is 0.85, σ=5.7 × 10-8 MKS units (A) 1230 J (B) 2325 J (C) 2115 J (D) 2315 J

Tardigrade Admin · Accepted Answer

From Stefan's law of radiation, the energy radiated

(E)

is given by

E = e σ T^{4} A t

Given,

e = 0.85, σ = 5.7 \times 1 0^{- 8}

,

T = 2000 K,

A = 5 \times 1 0^{- 5} m^{2}, t = 60 s

E = 0.85 \times 5.7 \times 1 0^{- 8} \times (2000)^{4} \times 5 \times 1 0^{- 5} \times 60

E = 2325 J

Q. Calculate the energy radiated per minute from the filament of an incandescent lamp at 2000K. If the surface area is 5×10−5m2 and its relative emittance is 0.85,σ=5.7×10−8 MKS units

1230 J

2325 J

2115 J

2315 J

From Stefan's law of radiation, the energy radiated (E) is given by E=eσT4At Given, e=0.85,σ=5.7×10−8, T=2000K, A=5×10−5m2,t=60s E=0.85×5.7×10−8×(2000)4×5×10−5×60 E=2325J

Q. Calculate the energy radiated per minute from the filament of an incandescent lamp at $2000 K$ . If the surface area is $5 \times 1 0^{- 5} m^{2}$ and its relative emittance is $0.85, σ = 5.7 \times 1 0^{- 8}$ MKS units

From Stefan's law of radiation, the energy radiated $(E)$ is given by
$E = e σ T^{4} A t$
Given, $e = 0.85, σ = 5.7 \times 1 0^{- 8}$ ,
$T = 2000 K,$
$A = 5 \times 1 0^{- 5} m^{2}, t = 60 s$
$E = 0.85 \times 5.7 \times 1 0^{- 8} \times (2000)^{4} \times 5 \times 1 0^{- 5} \times 60$
$E = 2325 J$