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In circuit breaker, to facilitate arc quenching, dielectric strength can be increased by

In circuit breaker, to facilitate arc quenching, dielectric strength can be increased by Correct Answer All of these

In circuit breaker, to facilitate arc quenching, dielectric strength can be increased by following methods.

Lengthening of the gap: The dielectric strength of the medium is proportional to the length of the gap between contacts. Therefore, by opening the contacts rapidly, higher dielectric strength of the medium can be achieved.

High pressure: If the pressure in the vicinity of the arc, is increased, the density of the particles constituting the discharge also increases. The increased density of particles causes higher rate of de-ionization and consequently the dielectric strength of the medium between contacts is increased.

Cooling: Natural combination of ionized particles takes place more rapidly if they are allowed to cool. Therefore, dielectric strength of the medium between the contacts can be increased by cooling the arc

Blast effect: If the ionized particles between the contacts are swept away and replaced by un-ionized particles, the dielectric strength of the medium can be increased consider-ably. This may be achieved by a gas blast directed along the discharge or by forcing oil into the contact space.

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