A perfect black body at 1000 K has surface area 0.1 m². Find n if energy radiated in 1 minute is about 3.4×10ⁿ J (σ=5.67×10⁻⁸ W m⁻² K⁻⁴).
Physics · Mixed Chapter
JEE Main Practice

Question

A perfect black body at 1000 K has surface area 0.1 m². Find n if energy radiated in 1 minute is about 3.4×10ⁿ J (σ=5.67×10⁻⁸ W m⁻² K⁻⁴).

G1 Physics · Accepted Answer

Step 1: Stefan–Boltzmann law P=σAT⁴. Step 2: P=(5.67×10⁻⁸)(0.1)(1000)⁴=5.67×10³ W. Step 3: Over 60 s, Q=Pt=(5.67×10³)×60=3.402×10⁵ J. Step 4: n=5.