Emergency blankets, often called "space blankets," are thin plastic sheets coated with a shiny, silver-colored metallic layer. They are wrapped around a person to prevent hypothermia by keeping them warm.
Why does the shiny, silver-colored surface help to reduce heat loss?
It conducts thermal energy efficiently from the surrounding atmosphere to the body.
It increases the rate of convection inside the blanket.
It reflects thermal radiation emitted by the body back toward the person.
It absorbs all thermal radiation from the surroundings to warm the person.
301 exam-style questions on CIE IGCSE Physics 2.3 Transfer of thermal energy, covering 2.3.1a Thermal conductors and thermal insulators, 2.3.1b Explaining thermal conduction, 2.3.2 Convection, 2.3.3a Thermal radiation, 2.3.3b Surface colour and texture, 2.3.3c Rate of emission and absorption of radiation, and 2.3.4 Consequences of thermal energy transfer. Each one has a worked solution and a mark scheme showing where the marks go.