Question

Which of the following is considered as the lowest rank of coal?
A. Peat
B. Lignite
C. Bituminous
D. None of the above

Answer 1

Hint: Coal is a combustible black or brownish black sedimentary rock which is formed when dead plant matter gets decayed over a long period of time.

Complete answer:
Coal contains carbon in major amounts but has other elements like hydrogen, sulfur, oxygen and nitrogen. It takes millions of years for the dead matter to get decayed and form coal. Coal is formed in different layers based on how dead matter is decomposed. Let us analyze the options to find out the correct option.

Option A: Peat is the first stage of transformation in the formation of coal. It has 40-55% of carbon and has more impurities. It burns like wood and leaves a lot of ash.Therefore, this is the incorrect option.

Option B: Lignite is also called brown coal which has 40-55% of carbon. It is the intermediate stage of coal formation. The moisture content is higher in lignite. It is also considered as lower grade coal. It has lower calorific value.Therefore, this is the correct option.

Option C: Bituminous is also called soft coal and contains 40-80% of carbon. It has a very high calorific value and is used in production of coke and gas.Therefore, this is the incorrect option.

Option D: Since one of the above mentioned captions is correct, this is the incorrect option.

Hence, the correct answer is option (B)

Note: Lignite has a lower rank in the coalification process, lower than bituminous and anthracite coals.