If the temperature of a black body is doubled, then its radiant emittance becomes:

Correct option is D

The correct answer is: (d) Sixteen times the original value
Explanation:
The radiant emittance (also known as total power radiated per unit area) of a black body is given by Stefan–Boltzmann Law:
ini
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E = σT⁴
Where:
• E is the radiant emittance
• σ is the Stefan–Boltzmann constant
• T is the absolute temperature in Kelvin
If the temperature T is doubled, then:
mathematica
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E' = σ(2T)⁴ = σ × 16T⁴ = 16E
So, the radiant emittance becomes 16 times the original value.