Electrical Engineering XYZ MCQs
Reactive power generated or delivered significantly depends on:
- Excitation
- Frequency
- Both of the above
- Load angle
Correct answer: 1. Excitation
Explanation: Reactive power is associated with the generation and delivery of electric power in alternating current (AC) systems. It is a measure of the power flow that does not perform any real work but is necessary for the establishment of magnetic fields in devices like motors and transformers.
Excitation refers to the process of supplying a magnetic field to the rotor windings of a synchronous machine, such as a generator. The excitation level, controlled by the field current, plays a crucial role in determining the amount of reactive power generated or absorbed by the machine. Proper excitation is essential for maintaining the voltage levels and power factor in the system.
Frequency and load angle also influence power system behavior, but they are not directly responsible for the generation or absorption of reactive power. Frequency is related to the speed of rotation of generators and is crucial for maintaining synchronization in the power system. Load angle is associated with the phase angle difference between the electrical rotor angle and the mechanical angle in a synchronous machine.
In summary, the generation or delivery of reactive power significantly depends on the excitation level, making “Excitation” the correct choice.