Tag: physics

Renewable- (b), (c) and (e); Non-renewable- (a), (d) and (f).
Here once petrol,diesel, coal and oil are consumed, for example in our vehicle, it cannot come back and renew to some other thing where as in wood, wind and water once we use it for some purpose we can use it for some other thing again like if wood is used in making bed then again we can make it back to wood or some other thing. Hence, these are renewable sources.

Unlike fossil fuels, trees are eternal sources of energy for animals. They absorb sunlight directly from the environment and keep on producing food for others as long as they exist.

Renewable-(b), (c) and (e); Non-renewable-(a), (d) and (f).
Here once petrol, diesel, coal and oil are consumed, for example in our vehicle, it cannot come back and renew to some other thing whereas in wood, wind and water once we use it for some purpose we can use it for some other thing again like if wood is used in making bed then again we can make it back to wood or some other thing. Hence, these are renewable sources.

Answer is D.

The heat produced by either steam or coal is converted in to electrical energy. Thus, in a thermal power station, heat energy is converted to electrical energy.

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 ($H _2S$).

Answer is C.

The heat from the earth's core continuously flows outward. It transfers (conducts) to the surrounding layer of rock, the mantle. When temperatures and pressures become high enough, some mantle rock melts, becoming magma. Then, because it is lighter (less dense) than the surrounding rock, the magma rises, moving slowly up toward the earth's crust, carrying the heat from below.
Sometimes the hot magma reaches all the way to the surface, where we know it as lava. But most often the magma remains below earth's crust, heating nearby rock and water (rainwater that has seeped deep into the earth) - sometimes as hot as 700 degrees F. Some of this hot geothermal water travels back up through faults and cracks and reaches the earth's surface as hot springs or geysers, but most of it stays deep underground, trapped in cracks and porous rock. This natural collection of hot water is called a geothermal reservoir.
Hence, the super-heated steam is raised in geothermal plants by the heat of magma or lava.

The steam comes from reservoirs of hot water found a few miles or more below the earth's surface. The steam rotates a turbine that activates a generator, which produces electricity Hence Geothermal energy can be used to produce electricity.

Build up of electrostatic charge in the clouds results in lightning. During this event, one region of the cloud is accumulated with positive charge whereas the other region is accumulated with negative charge.Hence when positive and negative charges grow large enough ,the air present being non-conductive no more resists the flow of charges and electric discharge can be seen in the form of giant lightning sparks.