Question

Which mirror is used in solar cooker

Answer 1

Concave mirror because it is a convergent mirror and focuses light to a single point increasing its intensity so that the food cooks faster.

Answer 2

concave mirror

This is because they are the only types of mirrors that reflect sunlight in towards a single focal point. If you use a convex mirror for your cooker, it will not work since they do not have a focal point.