Which type of process is currently used in nuclear electricity generation?

Why is charcoal considered to be a better fuel than wood? What are the disadvantages of converting wood into charcoal?

What percentage of solar energy can be converted into electricity by a modern solar cell?

Aditya suggests his family to install a solar water heater at their residence. But some of the family members were in favour of installing an electric geyser.
$(a)$ Who,according to you,is taking a correct decision? Mention the value exhibited by Aditya.
$(b)$ Also,give reasons (at least $2$) for your answer.

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

The longest and the shortest wavelengths (in $\mu m$) for red and violet light are respectively: