Question

The ultimate source of our energy is
(a)Sun
(b)Electricity
(c)Wind
(d)Plants

Answer 1

Hint: All the organisms present on the earth need an unending (renewable) and powerful source of energy to meet their daily requirements. Energy can neither be created nor be destroyed but is interconvertible.

Complete Answer:
- The Sun is an infinite and renewable source of energy which is also the most important source of energy for us.
- The energy from the sun is important for many processes such as photosynthesis, water cycle, nuclear energy, the formation of clouds, the formation of fossil fuels, etc. It provides light to the organisms required for their growth, daily activities, diurnal rhythm, etc.
- All our fossil fuels are derived from plants that existed millions of years ago. The sun's energy can also be stored.
- Plants convert the radiant energy of the sun into chemical energy (carbohydrates) with the help of water and carbon dioxide and store it in their leaves, trunk, and roots. This form of stored energy is also known as biomass energy. Biomass is a renewable source of energy.
- In addition to the direct solar power generated from solar thermal sources, coal, oil, natural gas, biomass, and even the wind and hydropower can be used to generate electricity. Solar energy helps in producing wind by changing the weather pattern.
- This wind is further used to produce wind energy and then electricity. Therefore, wind, electricity, and plants cannot be the ultimate source of energy. All of them originally derive their energy content from the sunlight only.

So, the correct answer is ‘Sun’.

Note: We can capture the thermal energy directly with the help of solar thermal panels and convert it into other forms. Alternatively, we can use photovoltaic (PV) cells, also called solar cells, to convert sunlight directly into electricity (‘photovoltaic’ essentially means ‘light electricity’).