A black body of area 1 cm 2 is at 1000 K ( = 5.67 10 -8 W m -2 K -4 ). The power it radiates is:

⚛️ Physics · Thermal Properties of Matter · NEET & JEE

A black body of area 1 cm2 is at 1000 K (σ = 5.67 × 10-8 W m-2K-4). The power it radiates is:

Answer: 5.67 W.

A 0.567 W
B 5.67 W
C 56.7 W
D 0.057 W

Correct answer: B. 5.67 W

Explanation: P = σAT4 = 5.67×10-8 × 10-4 × 1012 = 5.67 W.

During a phase change (melting or boiling), temperature stays constant while heat is absorbed entirely as latent heat (Q=mL); temperature only rises again once the substance is fully in its new phase.

Concept context

Temperature scales, thermal expansion, calorimetry, and the three modes of heat transfer including radiation laws.

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A black body of area 1 cm<sup>2</sup> is at 1000 K (&sigma; = 5.67 &times; 10<sup>-8</sup> W m<sup>-2</sup>K<sup>-4</sup>). The power it radiates is:

Concept context

More Thermal Properties of Matter questions

A black body of area 1 cm<sup>2</sup> is at 1000 K (σ = 5.67 × 10<sup>-8</sup> W m<sup>-2</sup>K<sup>-4</sup>). The power it radiates is: