The magnitude of field flux in a 3-phase synchronous motor?
Correct answer: D. remains constant at all loads
- A. varies with power factor
- B. varies with speed
- C. varies with the load
- D. remains constant at all loads
Explanation
With constant d.c. field excitation, the rotor field flux of a synchronous motor is essentially fixed as load changes; load mainly changes the load angle and armature reaction. Hence the field flux is treated as constant at all loads.
Last updated
Practise Electrical Machines
1,061 free Electrical Machines MCQs from Electrical Engineering, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Electrical Engineering questions like this
Electrical Engineering is on 2 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
5 H.P., 50-Hz, 3-phase, 440 V, induction motors are available for the following r.p.m. Which motor will be the costliest ?
A 220 V D.C. generator is run at full speed without any excitation. The open circuit voltage will be_____________?
A 3-phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor e.m.f. will be____________?
A 3-phase induction motor delta connected is carrying too heavy load and one of its fuses blows out. Then the motor______________?
A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor_______________?