Blackbody spheres A and B have radii 6 cm and 18 cm. Peak wavelengths are 500 nm and 1500 nm. Find ratio of total powers radiated Pₐ/Pᵦ.
Physics · Mixed Chapter
JEE Main Practice

Question

Blackbody spheres A and B have radii 6 cm and 18 cm. Peak wavelengths are 500 nm and 1500 nm. Find ratio of total powers radiated Pₐ/Pᵦ.

G1 Physics · Accepted Answer

Step 1: Wien’s law implies Tₐ/Tᵦ=λᵦ/λₐ=1500/500=3. Step 2: Stefan–Boltzmann law P=σ4πr²T⁴. Step 3: Pₐ/Pᵦ=(6/18)²×3⁴=(1/9)×81=9.