what happen when dc shunt motor field is sudden open in
running condition

Answer Posted / n.ravi teja

when dc shunt motor operates at normal conditions the speed
is constant.and when ever a suddenly field is open, the
field winding is having inductive property so it does not
allow sudden changes in current.open ckt means current
zero.and the rotor(armature) is continue its running
condition because it is connected to generator rotor
shaft.but we know when a current carrying cunductor is
placed in a rotating magnetic field ,it cuts the magnetic
field and emf is induced.but when field is open no current
carrying current is there in that ckt.so no emf is
induced.we know emf is proportional to speed.so speed
decreases .

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