Explanation:
In a low oil circuit breaker, the oil performs the function of arc extinction only.

Arc extinction:
When a circuit breaker interrupts a circuit, an arc is formed between the contacts due to the high current flowing through them. This arc needs to be extinguished to prevent damage to the circuit and ensure safe operation. The oil in a low oil circuit breaker is used to extinguish the arc.

The oil in the circuit breaker acts as a medium through which the arc is drawn out, cooled, and ultimately extinguished. When the contacts of the circuit breaker open, the current starts to decrease, but the ionized particles in the arc maintain the conductivity of the arc. The oil surrounding the contacts provides a path for the arc to be drawn out.

Insulation:
Insulation in a circuit breaker refers to the material or medium that prevents the current from flowing in unintended paths and ensures that it flows only through the desired circuit. In a low oil circuit breaker, the insulation is provided by other materials such as porcelain or ceramic, not by the oil.

Function of oil in a low oil circuit breaker:
The oil in a low oil circuit breaker primarily serves the purpose of arc extinction. It helps to draw out, cool, and extinguish the arc formed between the contacts when the circuit is interrupted. The oil also acts as a dielectric medium, providing support for the arc to be drawn out without damaging the contacts or other components of the circuit breaker.

Conclusion:
In conclusion, the oil in a low oil circuit breaker performs the function of arc extinction only. It helps to draw out, cool, and extinguish the arc formed between the contacts when the circuit is interrupted. The insulation in a low oil circuit breaker is provided by other materials such as porcelain or ceramic.