In case of an electric fire, it is crucial to select the appropriate fire extinguishing agent to ensure the safety of individuals and property. Among the given options (CO2, N2, SO2, Cl2), the correct choice is option 'A' - CO2 (carbon dioxide). Let's delve into why CO2 is the preferred fire extinguishing agent in electrical fires.

Electric Fire Hazards:
- Electrical fires can occur due to various reasons such as short circuits, overloaded circuits, faulty wiring, or equipment malfunction.
- These fires pose a significant risk as they can spread rapidly and cause damage to electrical systems and equipment, leading to power outages, property loss, and even endangering human lives.
- Traditional water-based fire extinguishing agents cannot be used on electrical fires as water conducts electricity and can cause electric shocks.

Properties of CO2:
- Carbon dioxide (CO2) is a colorless, odorless, and non-conductive gas.
- It is readily available and relatively inexpensive.
- CO2 is a clean agent that does not leave any residue, making it suitable for extinguishing fires in sensitive electrical equipment.
- It is non-toxic to humans and does not deplete the ozone layer.

Working Principle:
- CO2 works based on the principle of oxygen displacement.
- When CO2 is discharged onto a fire, it creates a dense blanket of gas that suffocates the fire by displacing oxygen, which is essential for combustion.
- By reducing the oxygen concentration to a level below which combustion cannot be sustained, CO2 effectively extinguishes the fire.

Advantages of CO2:
- CO2 is highly effective in suppressing electrical fires, as it does not conduct electricity.
- It can be safely used on live electrical equipment without the risk of electric shock to the operator.
- CO2 is suitable for extinguishing Class C fires, which involve energized electrical equipment.
- It has a rapid fire knockdown capability, quickly suppressing the flames and preventing further spread.
- CO2 is safe for use in confined spaces, as it does not produce any toxic byproducts.

Limitations:
- While CO2 is effective for electrical fires, it may not be suitable for all types of fires.
- It is less effective on deep-seated fires or fires involving combustible materials such as oil or wood.
- CO2 can displace oxygen in enclosed spaces, leading to an asphyxiation risk. Therefore, it should be used with caution, and the area should be properly ventilated after the fire is extinguished.

In conclusion, CO2 is the recommended fire extinguishing agent for electrical fires due to its non-conductive nature, oxygen displacement mechanism, and overall safety considerations. However, it is essential to assess the specific fire situation and consult with fire safety professionals to determine the most appropriate extinguishing agent for a particular scenario.