What kind of mirror − concave, convex or plain − would be best suited for use in a solar cooker

Q No. 1:

What kind of mirror − concave, convex or plain − would be best suited for use in a solar cooker? Why?

Ans:

A concave mirror would be best suited for use in a solar cooker because it reflect and focus the sunlight at a point. The temperature at that point increases which heats and cooks the food placed at that point.