Torque will remain constant
Torque will change but power will remain constant
shunt motor if the excitation is changed A. Torque will remain constant B. Torque will change but power will remain constant C. Torque and power both will change
Torque, power and speed, all will change
Answer is Wrong!
Answer is Right!
The correct answer is: C. Torque and power both will change.
Explanation:
The torque of a DC shunt motor is proportional to the field current. When the excitation is changed, the field current changes, and the torque changes accordingly. The power of a DC shunt motor is proportional to the square of the armature current. When the excitation is changed, the armature current changes, and the power changes accordingly.
Here is a more detailed explanation of each option:
- Option A: Torque will remain constant. This is incorrect because the torque of a DC shunt motor is proportional to the field current. When the excitation is changed, the field current changes, and the torque changes accordingly.
- Option B: Torque will change but power will remain constant. This is incorrect because the power of a DC shunt motor is proportional to the square of the armature current. When the excitation is changed, the armature current changes, and the power changes accordingly.
- Option C: Torque and power both will change. This is the correct answer because the torque and power of a DC shunt motor are both proportional to the field current. When the excitation is changed, the field current changes, and the torque and power both change accordingly.
- Option D: Torque, power and speed, all will change. This is incorrect because the speed of a DC shunt motor is proportional to the applied voltage. When the excitation is changed, the speed does not change.