The energy liberated by burning $1 \, g$ of wood is approximately: (in $, kJ/g$)

Mention the minimum wind velocity required for obtaining electric power with a windmill generator.

What is biomass? What can be done to obtain bio-energy using biomass?

Choose the only renewable source of energy from the following:

Ram visited Manikaran Sahib in Himachal Pradesh where he saw an experimental geothermal plant. When he saw a hot spring,he wanted to know more about it. His father explained to him about geothermal energy and hot springs. Now answer the following questions:
$(a)$ What did Ram's father explain to him about hot springs?
$(b)$ Why is geothermal energy not generated on a large scale?
$(c)$ What is the main advantage of using geothermal energy?

Name the process responsible for large energy production in the sun?