a) Increase of field strength b) Increase of mean free path c) High temperature d) All of these Ans: (d)
a) High resistance interruption b) Low resistance interruption c) Both (a) and (b) d) None of these Ans: (c)
a) Trip Coil b) Contacts c) Handle d) Medium Ans: (b)
a) Manually b) Automatically c) That it should give warning d) None of these Ans: (b)
a) Separation of circuit breaker and extinction of arc b) Separation of circuit breaker and rise of recovery voltage c) Normal current interruption and arc extinction d) None of these Ans: (a)
a) Restriking voltage b) Recovery voltage c) Rate of rise restriking voltage d) Active recovery voltage Ans: (c)
a) Closing time b) Opening time c) Both (a) and (b) d) None of these Ans: (d)
a) Lengthening of the gap b) Cooling c) Blast effect d) All of these Ans: (d)
a) Active recovery voltage b) Natural frequency of oscillations c) Both (a) and (b) d) Rating of circuit breaker Ans: (c)
a) Zero & infinite impedance before & after interruption respectively b) Infinity & zero impedance before & after interruption respectively c) Equal impedance before & after interruption d) None of these Ans: (a)