What will happen if field circuit becomes open in case of DC motor?

Answer: n d.c shunt motor if field winding supply is removed the motor back emf will drop to zero, hence the armature will draw more current to make up the emf. this results in blowing up of fuse.

What will happen if the field of the DC motor is opened accidentally in no load and full load?

The field will be reduced to only to the value of residual flux. The speed will be very high. The parts of motor may even fly apart.

What happens when field winding of a DC shunt motor opens while running?

If the shunt field suddenly opens while the motor is being operated under full-load conditions, only a small voltage due to the residual magnetism of the pole pieces will be induced into the armature. Current will increase considerably. The magnitude of this current may be sufficient to burn out the motor.

What will happen to the DC generator if the field winding attends the critical resistance?

If the field resistance of a d.c. generator is more than particular value ( critical resistance), The generator will fail to build up the voltage.

What would happen if the field of DC shunt motor is opened Mcq?

4. What will be the effect of opening of field of a DC shunt motor while motor is running? Explanation: In a DC shunt motor if supply for the field winding is cut down, the speed would dangerously increase in order to maintain the back emf of the motor.

What happens if field winding of the synchronous motor is short circuited?

In the case of an induction motor, the field winding is permanently short-circuited by end rings. In a Synchronous motor, the rotor winding is supplied with DC excitation. Therefore if we short circuit the field winding of a synchronous motor then it will behave as an induction motor.

What will happen if DC shunt motor running on no load has shunt field winding opened accidentally?

Ans: if a shunt motor, running at no load has its shunt field opened or burnt out, the back emf will fall to nearly zero . the armature current will continuously increase the speed of the motor until its parts fly apart.

What will happen if the shunt field winding of a loaded shunt motor accidentally breaks?

Ans: if the shunt field winding of a loaded shunt motor accidentally breaks, the loss of shunt field current would result in stopping of the motor or burn out the armature or fuse.

What is the effect on speed if part of the field winding is shorted?

If field winding is disconnected accidentally, the speed would dangerously increase in order to maintain the back emf of the motor. For a constant back emf, flux is inversely proportional to the speed of the motor.

What will happen if field resistance is decreased for a DC generator?

What will happen if field resistance is decreased? Explanation: When field resistance is decreased, it will increase field current by Ohm’s law. Thus, field resistance line will lie below the older line of field resistance. Eventually, it’ll intersect OCC afterwards causing increase in no-load voltage.

What happens if you cut off the field winding of DC motor?

As for shunt motor, speed is inversely proportional to field current, so cutting off the field winding results in dangerously high speed. Thus motor gets damaged. However for series dc motor, cutting off the field winding simply decreases the speed of the motor and the motor stops. Hope this helps:)

What happens if you cut off the supply for field winding?

In a DC series motor, if you cut off the supply for the field winding it means you have cut the supply off the motor as the field is in series with the armature. So it will simply come to rest after sometime.

What happens if the terminals of a DC series motor are opened?

The field winding of a DC series motor is in series with the armature winding. So, if the terminals of the field winding are opened then current will stop flowing in the entire circuit. The motor will slow down due to friction and eventually stop.

What is a field winding opening in a series motor?

In case of a series machine field winding opening means that the motor circuit is open and no current will pass through armature , for operation of machine interaction of two fluxes is necessary thus the machine won’t operate. How this 19-year-old earns an extra $3600 per week.