Question

The biggest source of energy on Earth’s surface is
(a)Coal
(b)Tides
(c)Atoms
(d)Solar radiations

Answer 1

Hint: The biggest source of energy is the basis of the food chain as the plants use this energy for getting their food. It regulates the weather and provides a liveable environment for all living creatures as it is also responsible for the water cycle.

Complete answer:
Solar radiation is the biggest source of energy on Earth’s surface. The Sun has been radiating from nearly 5 billion years producing an enormous amount of energy at the present rate and will continue to do so for another 5 billion years more. A part of solar energy reaches the earth’s atmosphere and nearly half of it is absorbed by the atmosphere. The rest of the radiation reaches the earth’s surface. The energy can be used only at certain times during the day so is limited and solar cells are used to convert solar energy into electricity. A single solar develops a voltage of 0.5 to 1 Volts and can produce an average of 0.7 Watts when exposed to the Sun. A large number of solar cells are arranged together to form a solar cell panel. It can deliver electricity for practical use. The advantages of solar cells or photovoltaic cells are that they have no moving parts, require little maintenance, and can be set up in remote areas and very sparsely inhabited areas where laying of a power transmission line may be costly or may not commercially viable. But the entire process of manufacture is very expensive. Wind currents are possible as the sun heats the Earth’s surface and the Earth heats the air above. Water evaporates by the sun and forms clouds to give rain.
So, the correct answer is ‘Solar radiations’.

Note: The sun radiations are not always safe. The ozone layer is present in the stratosphere and functions as a shield against harmful UV- radiation. In the absence of this layer, the extremely harmful UV radiations will reach earth and cause great harm to organisms. But some factors lead to the depletion of the ozone layer like chlorofluorocarbons (CFCs) and halons. These gases formerly found in aerosol spray cans and refrigerants are released into the atmosphere which causes chemical reactions that break down ozone molecules, reducing ozone's ultraviolet radiation-absorbing capacity.