Question

______ is the common variety of coal used in households.
A. Anthracite
B. Bituminous
C. Peat
D. Lignite

Answer 1

Coal is basically a combustible black or brownish-black sedimentary rock which is formed as a rock strata called as coal seams. Coal is mainly the carbon consisting of variable amounts of other elements which include chiefly hydrogen, oxygen, sulphur, and nitrogen.

Complete answer:
There are mainly four types of coal which include anthracite, bituminous, sub bituminous and lignite. Let us briefly discuss different types of coal mentioned in the options one by one:
- Option A: Anthracite is a hard, brittle, or black lustrous coal which is generally referred to as the hard coal. It comprises a high percentage of the fixed carbon and comparatively a low percentage of volatile matter. It possesses clean burning properties. Therefore, this type of coal is commonly used in households.
- Option B: Bituminous coal usually possesses a high heating (Btu) value and hence, it is more commonly used in the generation of electricity.
- Option C: Peat is not actually coal. Rather, it is the precursor to coal. It is actually a soft organic material comprising partly decayed plant or sometimes deposited mineral matter. Peat can lead to the formation of coal when it is placed under high heat and pressure.
- Option D: Lignite is actually the lowest grade coal having the least concentration of carbon.

**Hence, the correct answer is Option A.

Note:**
In terms of the performance as well as the heating standpoint, anthracite is considered to be a higher quality coal for domestic and open fire heating. Since anthracite is harder to ignite, it does burn for a longer time period at a hotter temperature, which means that it is more effective in providing the reliable warmth for your household.