What type of reactions occurring inside the sun produce solar energy?

Q. Solar energy is produced by the following reaction

Q. Sun gets its energy through ______ occurring inside it.

Q. Hydrogen atoms undergo fusion reaction which produces the heat inside the sun.

Q. A surface of area $1m^2$ kept perpendicular to the sun rays absorbs $1.8MJ$ of solar energy in one hour.
(a) What is the amount of electrical energy produced when a solar panel of area $5m^2$ is exposed perpendicular to the sun rays for $5h$. Take the efficiency of solar panel as 30%.
(b) Calculate the power generated in $kW$.