Question

A perfect black body has an emissivity value of ______.

Options

• 0

• 0.5

• 1

• Infinity

Answer 1

A perfect black body has an emissivity value of 1.

Explanation:

Emissivity (e) is a measure of how efficiently a body emits thermal radiation compared to an ideal black body. For a perfect radiator (black body), e = 1, meaning it emits the maximum possible radiation at a given temperature.