In an experiment a student records several values of total emissive power,

PHYSICS · Multi-part · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter

Problem

E

, for different absolute temperatures,

T

, of a blackened metal surface. A straight-line graph of

E

(vertical axis) against

T^4

(horizontal axis) gives a slope of

5.8 \times 10^{-8}\,\text{W}\,\text{m}^{-2}\,\text{K}^{-4}

. (i) Calculate the value of the Stefan–Boltzmann constant obtained from this experiment. (ii) The accepted value of the constant is

5.67 \times 10^{-8}\,\text{W}\,\text{m}^{-2}\,\text{K}^{-4}

. Determine the percentage error in the student’s result. (iii) Suggest one possible experimental factor that could account for the observed error.