·High resistance method – In this method arc resistance is made to increase with time so thatcurrent becomes insufficient to maintain the arc. Disadvantage of this method is enormous energy is dissipated in the arc. Hence it can be used only in dc circuit breakers and low capacity ac circuit breakers. Arc resistance can be increased by: 1.Lengthening the arc – Arc resistance is directly proportional to length of arc so to increase resistance separation between the contacts are increased 2.Cooling the arc – Cooling helps in deionisation of medium thus increasing arc resistance 3.Reducing cross section of the arc – When area of arc reduced, voltage necessary to maintain arc increased i.e. resistance is increased. Allowing the arc to pass through narrow opening can reduce cross read more

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