Question

why is a concave mirror used in some solar cooker in place of plane morror

Answer 1

Concave mirror is used in some solar cooker in place of plane mirror as the concave mirror acts as a converging mirror which converges the light in one point falling on it, thus increasing the temperature.

Answer 2

Explanation:

A concave mirror is used in a solar cooker as it uses heat of the sunlight to cook food. The mirror focuses all the incident sunlight at a point. The temperature at that point increases, thereby cooking and heating the food placed at that point.