Fill in the following blanks with suitable words :

A solar cell converts …………………. energy into …………………. energy.

Name the devices which converts sunlight into electricity.

How much solar energy will be received by 1 m² area in one hour if the solar constant be 1.4 kW/m²?

What is the difference between a thermal power plant and hydro power plant?

Which of the two causes serious air pollution and how?