In case of D.C. shunt motors the speed is dependent on back e.m.f. only because
A. Back e.m.f. is equal to armature drop
B. Armature drop is negligible
C. Flux is proportional to armature current
D. Flux is practically constant in D.C. shunt motors
Answer: Option D
Solution(By Examveda Team)
In the case of D.C. shunt motors, the speed is dependent on back e.m.f. only becauseFlux is practically constant in D.C. shunt motors.In a shunt motor, the field winding is connected in parallel with the armature winding. This configuration ensures that the flux (magnetic field) remains relatively constant, regardless of changes in load or speed.
As a result, the back electromotive force (e.m.f.) generated in the armature is primarily determined by the speed of the motor and not significantly affected by changes in the flux.
Therefore, the correct option is Flux is practically constant in D.C. shunt motors.
This Question Belongs to Electrical Engineering >> D.C. Motors
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Comments ( 1 )
The condition for maximum efficiency for a D.C. generator is
A. Eddy current losses = stray losses
B. Hysteresis losses = eddy current losses
C. Copper losses = 0
D. Variable losses = constant losses
If a D.C. motor is connected across the A.C. supply it will
A. Run at normal speed
B. Not run
C. Run at lower speed
D. Burn due to heat produced in the field winding by eddy currents
The speed of a D.C. shunt motor can be increased by
A. Increasing the resistance in armature circuit
B. Increasing the resistance in field circuit
C. Reducing the resistance in the field circuit
D. Reducing the resistance in the armature circuit
The armature voltage control of D.C. motor provides
A. Constant torque drive
B. Constant voltage drive
C. Constant current drive
D. None of the above
For dc Motor,
Eb proportional to flux and speed
In dc shunt motor, the flux is practically almost constant. Hence the speed of the motor is only depend on e.m.f.