Speed of DC motor can be controlled by varying ___

Speed of DC motor can be controlled by varying

A. Applied voltage.
B. Its flux per pole.
C. Resistance of armature culture.
D. All of these.

Show Answer

Answer: D

Share your understanding of this question with the correct explanation.

The speed of a DC motor can be controlled by varying all of the following:

A. Applied voltage: By increasing or decreasing the applied voltage to the motor, the speed can be adjusted. A higher voltage will increase the speed, while a lower voltage will decrease the speed.

B. Flux per pole: The speed of a DC motor is directly proportional to the flux per pole. By varying the field current or the field winding configuration, the flux per pole can be adjusted, thereby controlling the motor speed.

C. Resistance of armature circuit: By changing the resistance in the armature circuit, such as through the use of a variable resistor or a rheostat, the speed of the motor can be regulated. Increasing the resistance in the armature circuit decreases the current and hence the speed, while reducing the resistance allows more current and increases the speed.

Therefore, the correct answer is D: All of these. The speed of a DC motor can be controlled by varying the applied voltage, the flux per pole, and the resistance in the armature circuit. These control methods offer flexibility in adjusting the speed of the motor to suit specific operational requirements.