(a) Define thermal resistance of a plane slab and state how it depends on the…
PHYSICS · Subjective · CBSE · Physics · Thermal Properties of Matter · Thermal Properties of Matter
Problem
(a) Define thermal resistance of a plane slab and state how it depends on the physical and geometrical properties of the material.
(b) A dwelling is provided first with a roof made of reinforced concrete and later a layer of mineral wool is laid above the roof slab. Explain, without using any numerical calculation, why the rate of heat loss through the roof does not continue to fall in the same proportion when successive equal layers of the same insulator are added.
(c) Briefly describe how the concept of thermal resistances in series helps an engineer to decide the point beyond which increasing the thickness of insulation gives little economic benefit.