Radiation Problem: Find Surface Area of Light Bulb Filament

  • Thread starter Thread starter brilapwnzall
  • Start date Start date
  • Tags Tags
    Radiation
Click For Summary
SUMMARY

The problem involves calculating the surface area of a light bulb filament given its temperature, power output, and emissivity. The correct formula to use is \(\Delta Q/\Delta T = e \sigma A T^4\), where \(\sigma\) is the Stefan-Boltzmann constant (5.67 x 10^-8 W/m²K⁴). The temperature must be converted from Celsius to Kelvin before applying the formula. The correct surface area calculation yields approximately 0.000261 m², correcting the initial miscalculation due to the temperature conversion error.

PREREQUISITES
  • Understanding of the Stefan-Boltzmann Law
  • Knowledge of temperature conversion from Celsius to Kelvin
  • Familiarity with emissivity in thermal radiation
  • Basic algebra for solving equations
NEXT STEPS
  • Study the Stefan-Boltzmann Law in detail
  • Learn about emissivity and its impact on thermal radiation
  • Practice temperature conversions between Celsius and Kelvin
  • Explore practical applications of thermal radiation in engineering
USEFUL FOR

Students in physics or engineering courses, educators teaching thermodynamics, and anyone interested in the principles of thermal radiation and heat transfer.

brilapwnzall
Messages
1
Reaction score
0

Homework Statement


The filament of a light bulb has a temperature of 3.2*10^3°C and radiates 59 watts of power. The emissivity of the filament is 0.38. Find the surface area of the filament.

Homework Equations



\DeltaQ/\DeltaT=e\sigmaAT^4

\sigma=5.67*10^-8

The Attempt at a Solution



59=(.38)(5.67*10^-8)(A)(3.2*10^3)^4

Use needed Algebra to solve for A and I get 2.61e-5, but it's not the right answer.
Can someone please tell me what I am doing wrong?
 
Physics news on Phys.org
Your temperature 3.2*10^3°C is in Celsius, you need to convert it to Kelvin (K).
 
What temperature scale is implied by the Stefan-Boltzmann constant?
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
12
Views
8K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 12 ·
Replies
12
Views
9K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
15
Views
3K
  • · Replies 1 ·
Replies
1
Views
6K