Question

temperature of a black body is increased from 200k to 400k how will the ratio of heat emission changes

Answer 1

Heat emission will increase 16 times .

q₄₀₀ = 16 q₂₀₀

Explanation:

heat emission by a black body is given by stefen law:

q = σT⁴

q is the heat emission , T is temperature

σ ≈ 5.67 × 10−8 W/(m2K4)

q∝ T⁴

q₁ /q2 = T₁⁴ / T₂⁴

         = 200⁴ / 400⁴

    q₁ /q2     = 1/16

means q₂ = 16 q₁

heat emission will increase 16 times .

q₄₀₀ = 16 q₂₀₀