A student has set up a solar cooker in a box using a black painted aluminium sheet, a black cooking vessel, some glass wool , a transparent glass sheet and a mirror plate. What is the role of black paint, transparent glass sheet and a mirror used in the solar cooker ?

What is the role of a plane mirror and a glass sheet in a solar cooker?

What is the role of a plane mirror and a glass sheet in a solar cooker ?

What is the use of a glass sheet in solar heating devices ?

Why is the box of a solar cooker painted black from inside ?

Two students made box-type solar cookers separately. They both painted the insulated box with black colour from inside, the cooking pots were painted black from outside, and a plane mirror reflector was also attached. One of the students covered the solar cooker box with a transparent glass sheet but the other student covered the solar cooker box with a transparent plastic sheet. Which of the two solar cookers will be more efficient and why ?

(a) Explain why, a solar cooker box is (i) painted black from inside, and (ii) covered with a glass sheet. (b) Give two reasons why biogas is a good domestic fuel.