What is the full form of CNG?  

Compressed natural gas

The correct answer is option 1. Compressed natural gas.

CNG stands for Compressed Natural Gas. It is a form of natural gas that has been compressed to a pressure higher than atmospheric pressure for transportation and storage. Here's a brief explanation:

1. Composition:  Compressed Natural Gas primarily consists of methane (CH₄), which is the main component of natural gas. It may also contain small amounts of other hydrocarbons, nitrogen, carbon dioxide, and trace elements.

2. Production: CNG is produced by compressing natural gas to reduce its volume and increase its energy density. Compression is typically done using special compressors, and the resulting CNG is stored in high-pressure containers.

3. Use as a Fuel: CNG is used as a fuel in vehicles, especially in automobiles designed or modified to run on compressed natural gas. It is considered a cleaner alternative to traditional liquid fuels like gasoline or diesel because it produces lower levels of pollutants during combustion.

4. Advantages: CNG is more environmentally friendly compared to traditional fuels, as it produces fewer emissions of pollutants such as carbon monoxide, nitrogen oxides, and particulate matter. It is a cost-effective fuel, and its combustion is generally more efficient.

5. Storage and Distribution: CNG is stored and distributed in high-pressure cylinders or tanks. Fueling stations equipped with compressors are used to fill the CNG tanks of vehicles.

CNG is commonly used in public transportation, commercial fleets, and private vehicles as a cleaner and more sustainable fuel option, contributing to efforts to reduce air pollution and dependence on traditional fossil fuels.