Question

Which one of the following is not a renewable source of energy?
A. Wood
B. Alcohol
C. Biogas
D. Coal

Answer 1

Hint: Renewable sources of energy – The energy sources that are freely available in nature and the chances of their exhaustion are minimal. These energy sources are regularly being produced in nature.

Complete answer:Non – renewable sources of energy – The energy sources that are not freely available in nature and the chances of their exhaustion are very certain. These energy sources take thousands of years to be produced in nature.
Wood is a renewable source of energy. It is being constantly produced in nature by plants.
Alcohol is also a renewable source of energy that can be produced synthetically also.
Biogas is the product of anaerobic digestion of animal excreta. It is produced by microorganisms.
Coal is a non – renewable source of energy. It takes thousands of years to form coal in nature.

Additional information: Coal and petroleum are fossil fuels. They are formed by the fossilization of dead remains of plants and animals respectively. Over a period of thousands of years, the dead remains of plants and animals get converted to organic matter. This occurs due to extreme pressure and temperature conditions in the layers of deposits. The extreme temperature and pressure lead to a change in form of the dead remains.

So the correct answer is D. Coal

Note: Biogas is a form of biofuel that is naturally produced from the decomposition of organic waste.
When organic matter, like food scraps and animal waste, breaks down in an anaerobic environment (an environment absent of oxygen) they release a blend of gases, mainly methane and carbon dioxide.