A solid metallic sphere of radius 5.0 cm behaves approximately like a perfect blackbody
PHYSICS · Subjective · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
A solid metallic sphere of radius 5.0 cm behaves approximately like a perfect blackbody.
(i) The wavelength corresponding to its maximum spectral intensity is initially measured to be 965 nm. Calculate the initial absolute temperature of the sphere.
(ii) The sphere is then heated electrically until the radiant power emitted per unit surface area becomes nine times the initial value. Determine the new temperature attained.
(iii) For the temperature obtained in part (ii), find the new wavelength of peak emission.
(iv) Using your results above, compute the total radiant power emitted by the sphere before and after heating.
(Take Wien’s constant b=2.898×10−3mK and Stefan–Boltzmann constant σ=5.67×10−8Wm−2K−4.)