The filament of an incandescent lamp of power 64 W is made of Tungsten. The operation temperature of the lamp is 2000 K. Consider the filament a black body and find its radius (in mm). [Given: σ=6 × 10-8 W / m 2 length of filament is (10/3 π) cm ]

Question

The filament of an incandescent lamp of power 64 W is made of Tungsten. The operation temperature of the lamp is 2000 K. Consider the filament a black body and find its radius (in mm). [Given: σ=6 × 10-8 W / m 2 length of filament is (10/3 π) cm ] (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

64=σ T 4(2 π r l) .r =10-3 m =1 mm )

Q. The filament of an incandescent lamp of power $64 W$ is made of Tungsten. The operation temperature of the lamp is $2000 K$ . Consider the filament a black body and find its radius (in $mm$ ).
[Given : $σ = 6 \times 1 0^{- 8} W / m^{2} &$ length of filament is $\frac{10}{3 π} c m$ ]

$64 = σ T^{4} (2 π r l)$
$r = 1 0^{- 3} m = 1 mm)$

Q. The filament of an incandescent lamp of power 64W is made of Tungsten. The operation temperature of the lamp is 2000K. Consider the filament a black body and find its radius (in mm). [Given : σ=6×10−8W/m2& length of filament is 3π10​cm ]

64=σT4(2πrl) r=10−3m=1mm)

Q. The filament of an incandescent lamp of power $64 W$ is made of Tungsten. The operation temperature of the lamp is $2000 K$ . Consider the filament a black body and find its radius (in $mm$ ).
[Given : $σ = 6 \times 1 0^{- 8} W / m^{2} &$ length of filament is $\frac{10}{3 π} c m$ ]

$64 = σ T^{4} (2 π r l)$
$r = 1 0^{- 3} m = 1 mm)$