What are fossil fuels? Name any three fossil fuels.

Name any two renewable sources of energy.

There are about $50$ teachers in a school and most of them come to school by their own cars. Many of the teachers come from the same place but everyone prefers to come to school by his/her own car.
Answer the following questions based on the above information:
$(a)$ Do you think that their practice of commuting to school is environmental-friendly? Give one suggestion. Justify your answer.
$(b)$ In what other two ways can we become environmental-friendly?

In a box-type solar cooker,what is the range of temperature that can be achieved in two or three hours?

Name any two materials that are used to make solar cells.

$A$ student constructed a box-type solar cooker. He found that it did not work efficiently. Give any four possible mistakes in the construction and operation of the solar cooker.