In a minimum oil circuit breaker, the oil is used

to act as circuit breaking medium only

for circuit breaking and providing insulation

for providing insulation only

for none of the above purposes

Bulk oil type circuit breaker

Air blast circuit breaker

Vacuum circuit breaker

Sulphur hexafluoride circuit breaker

Air blast circuit breaker

Sulphur hexafluoride circuit breaker

Oil circuit breaker

Vacuum circuit breaker

Air blast

Minimum oil

Bulk oil

Sulphur hexafluoride

to produce insulation effect

to stop the ionisation of the surrounding air

to ensure the operation of the device at a low temperature

to suppress the sparking produced across the connector at the time of breaking a circuit.