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Heat Transfer - Engineering

Q1:

Absorptivity and refletivity of a perfect black body are respectively

A 1 and 0

B 0 and 1

C 1 and ∞

D 0 and 0.5

ANS:A - 1 and 0

The correct statement is: b) Absorptivity and reflectivity of a perfect black body are 0 and 1, respectively. A perfect black body is defined as an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. As a result, it reflects no radiation and absorbs all incident radiation. Therefore, its absorptivity is 1 (or 100%), and its reflectivity is 0 (or 0%).