Question

Which is better domestic fuel?
A. CNG
B. LPG
C. Wood
D. Coal

Answer 1

Hint: Before deciding which fuel is better, let’s know what a fuel is. Fuel is a substance in which carbon atoms are the major constituent. Since carbon atoms are the major content in fuels, it is highly combustible and produces large amounts of heat.

Complete step by step answer:
Fuels are generally of two types on the basis of their occurrence and physical state. Based on the occurrence, fuels are divided into two, i.e. natural and artificial fuels. Natural fuels are also known as primary fuels and artificial fuels are also known as secondary fuels. Some examples of natural fuels are wood, coal, petroleum, natural gas etc. Examples of artificial fuels are kerosene, petrol, coke etc.
Now let’s focus on the options.
A. Compressed Natural Gas is abbreviated as CNG. It contains mostly methane. It is termed as clean fuel. It has a low calorific value and it is used as a refrigerant. Since it has very high ignition temperature and volatile nature, it is not used as cooking gas.
B. Liquefied Petroleum Gas is abbreviated as LPG. It is used for cooking. It has a very high calorific value and thus can cook quicker than other fuels. It does not have any odor and releases less amount of greenhouse gases.
C. Wood produces a large amount of smoke when it is burnt since it has a very low calorific value. Thus cannot be considered as a better fuel.
D. Coal is similar to wood. It also produces smoke.
Hence LPG is a better domestic fuel.

So, the correct option is B .

Note: The given table represents the differences between LPG and CNG.

LPG	CNG
High ignition temperature	Low ignition temperature
Constituents are propane and butane	Constituent is methane
Calorific value is $90 - 95{{MJ}}.{{{m}}^{ - 3}}$	Calorific value is $35 - 40{{MJ}}.{{{m}}^{ - 3}}$
Used as cooking gas in homes and restaurants	Used as refrigerant and automobile fuel
Highly flammable	Less risk of ignition