Energy Resources and Storage

Coal is primarily composed of carbon, which is a single element. Petroleum is a complex mixture of hydrocarbons, while water and air are not elemental energy sources in the same sense.

This is the correct option. Petroleum, coal and natural gas are the exhaustible resources. Their amount present in the earth is limited.

Water stored at a height in a dam reservoir possesses gravitational potential energy due to its position relative to the ground. This energy is converted into kinetic energy as the water flows down through the turbines.

Biogas is a clean and efficient fuel. It is a mixture of methane (CH₄), carbon dioxide (CO₂), hydrogen (H₂) and hydrogen sulphide (H₂S).The chief constituent of biogas is methane (65%). 

fact The electrical energy is produced from other natural sources.

Geothermal energy comes from heat sources within the Earth, such as volcanoes, hot springs, and geysers. Coal is a fossil fuel formed from ancient plant matter, not a source of Earth's internal heat.

Conventional sources of energy are those that have been used for a long time and are generally non-renewable or traditional, such as fossil fuels or large-scale hydroelectric power. Solar, geothermal, and wind are considered non-conventional or renewable sources.

This is the correct option. Sunlight is not an exhaustible natural resource.

Thermal power stations, which primarily use coal, generate the largest amount of electricity in India.

This is the correct answer as both statements b and c are false.

Unleaded petrol is not an alternative form of fossil fuel.

Water is a renewable source of energy. Water flowing downstream is a powerful force. Water is a renewable resource, constantly recharged by the global cycle of evaporation and precipitation. The heat of the sun causes water in lakes and oceans to evaporate and form clouds.  

Coal is not a non-conventional source of energy.  Coal is very widely used as a source of energy. It provides employment to over 7 lakh workers. Its reserves are substantial. Coal has a favour over other fuels as it can be converted into other forms of energy. 

Wood is a renewable source of energy. This is because, we can burn recently grown wood, and we can plant more trees. When oil or coal is used up, it's gone and can't be replaced.