Question

Why should solar cookers be covered with glass plates?

Answer 1

Hint: Glass plates trap the heat inside the cooker whereas a steel plate does not. Heat can travel inside the cooker through a glass plate but it’s hard for the heat to escape outside.

Complete step by step answer:
Solar cookers is a device that uses the energy of direct sunlight to heat or cook food materials. The sun rays pass through the glass plate and get absorbed inside the cooker. The glass plate traps larger amounts of heat to use in heating the food item than a steel plate.
As the heat from the sun goes inside the solar cooker, this heat needs to be trapped inside the cooker so that the temperature may remain enough to heat the food, so to trap this heat so that it does not escape back out from the cooker; a glass plate is kept which keeps the heat inside the cooker for a long time.So the glass plate allows solar radiation to pass through it but it does not allow the heat radiation from inside to escape outside whereas a steel plate cannot do this.

Note:Solar radiation is a radiant energy emitted by the sun from a nuclear fusion reaction that creates electromagnetic energy. Sunlight is actually solar radiation. Sunlight is very useful as well as very harmful. Nuclear fusion is a process in which two or more nuclei combine to form a single nucleus.