What are the drawbacks of using nuclear energy?

Name the reaction responsible for large energy production in the sun.

What is the effect of light on the conductivity of a semiconductor used in solar cells?

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?

What is the minimum wind velocity required for obtaining useful energy from a windmill?

How is the slurry left over after the generation of biogas in a biogas plant used?