A student constructed a model of box-type solar cooker. He used a transparent plastic sheet to cover the open face of the box. He found that this cooker does not function well. What modification should he make to enhance its efficiency ? Give reason.

A student constructed a box-type solar cooker and covered it with a glass place. Write the purpose served by the glass plate in the cooker.

A student constructed a box type solar cooker. He found that it did not work efficiently. What could this be due to ? Give any four possible mistakes in the construction and operation of the cooker. What maximum temperature can ordinarly be reached inside a solar cooker ?

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 ?

In order to make an efficient solar cooker, the cover of cooker box should be made of :

(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.

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 ?