Question

A black body at 1000°c radiates 14.89 watt per square centimetre of its surface. The surfaceof a certain star radiates 10 kW per square centimetre. Assuming that the star’s surface behaves as a perfect blackbody, estimate its temperature.

Answer 1

Data: T₁ = 273 + 1000 = 1273K,

R₁ = 14.89 watt/cm² = 14.89 × 10⁴ watt/m²,

R₂ = 10 kW/cm² = 10⁷ watt/cm²

Emissive power of a blackbody, R = σT⁴

∴ This is the temperature of the star’s surface.