JAMB - Physics (2025 - No. 22)
Which of the following has the least thermal conductivity?
air
ash
glass
water
Paskaidrojums
Answer: A. air
(Air is a poor conductor ~0.025 W/mK; water ~0.6, glass ~1, ash varies but is higher.)
Air is a poor conductor of heat compared to solids and liquids like ash, glass, and water, making it a good insulator.