What is a solar cell? What is its other name?

State whether the following statement is true or false:
Solar energy has the greatest potential of all the renewable sources of energy.

Give two uses of coke.

Choose the correct statement.

Ranvir lives in a village and uses wood as a fuel. He studied in his school that charcoal is a better fuel than wood. He decided to use charcoal instead of wood.
$(a)$ How can Ranvir obtain charcoal from wood?
$(b)$ Why is charcoal considered a better fuel than wood? (Give two reasons)

Name two combustible components of biogas.