Tag: sources of energy

Answer is B.
Windmills, like waterwheels, were among the original prime movers that replaced animal muscle as a source of power. They were used for centuries in various parts of the world, converting the energy of the wind into mechanical energy for grinding grain, pumping water, and draining lowland areas.
Kinetic energy of the wind is transformed into mechanical energy of the turning windmill. This can be used to turn a generator to generate electricity. The original energy to cause the wind to blow came from the sun. Uneven heating of the earth's surface causes wind.
Hence, the statement is false.

Answer is B.

Biogas is characterized based on its chemical composition and the physical characteristics which result from it. It is primarily a mixture of methane (${ CH } _{ 4 }$) and inert carbonic gas (${ CO } _{ 2 }$). However the name 'biogas' gathers a large variety of gases resulting from specific treatment processes, starting from various organic waste - industries, animal or domestic origin waste, etc . 
Hence, the statement is false.

Fuel-grade ethanol is one energy source that has great potential for being generated from biomass. The gas obtained by the fermentation of biomass is called biogas.

Biogas is a type of secondary energy because biomass (primary energy) is used to produce biogas by anaerobic digestion into more efficient and higher value fuel.Biogas is also called gobargas as made by waste remains of plants and animals.

Major gases released from biomass are methane ($CH _4$), carbon dioxide ($CO _2$), hydrogen ($H _2$) and hydrogen sulphide ($H _2S$).

Renewable energy obtained from the ocean is together termed as ocean energy. Thus, ocean energy can be classified into various categories such as ocean thermal energy, tidal energy and wave energy.