Question

Why is the roof of buildings painted white?

(a) Because it absorbs radiation

(b) Because it reflects radiations

(c) Because it is cheaper

(d) Because it conducts heat

The question was asked by my college professor while I was bunking the class.

This question is from Thermal Conductivity in portion Thermal Properties of Matter of Engineering Physics I

Answer 1

The correct choice is (b) Because it reflects radiations

Easiest explanation: Black objects are good absorbers and radiators while white surfaces are poor absorbers and radiators. Therefore houses are painted white to keep the building cool during summer.