Mention two disadvantages of using animal dung directly as a fuel.

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?

What is the basic cause for winds to blow? Name a part of India where wind energy is commercially harnessed. Compare wind power and power of water flow in respect of generating mechanical and electrical energies. What is the hindrance in developing them?

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

What is the most important characteristic of a good fuel?

State any two impacts on the environment caused due to the increase in energy demand. Suggest any two steps to reduce energy consumption.