Q. Which one of the following is not a non-conventional source of energy?
Answer: Natural Gas
Notes: Non-conventional energy, also known as renewable energy, refers to energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Non-conventional energy sources are infinite, natural, and restorable. Natural gas is a conventional source of energy.