Electrical Engineering XYZ MCQ
Which of following is an advantage of per unit system:
- It needs impedance transformations
- Simplifies comparison
- Quantities are measured in usual units
- All of these
Correct answer: 2. Simplifies comparison
Explanation: The per unit system is a method of expressing electrical quantities in a normalized or dimensionless form. In this system, all quantities are expressed in per unit (pu) values, and these values are ratios or percentages. The advantage of the per unit system is that it eliminates the need to deal with actual units, making calculations and comparisons more convenient.
Using per unit method impedance transformations can be avoided, circuits containing many transformers can be solved easily with less chance of error. Per-unit systems allow for easy and direct comparisons of quantities such as current, voltage, and impedance across different components or systems. It simplifies the analysis and evaluation of electrical systems.
In per unit system, quantities are not measured in their usual SI units e.g volts, amperes, watts, ohms. Instead, each electrical quantity is measured as a decimal fraction of so me base level.
So from given options in this Electrical Engineering XYZ MCQ, the correct option is “Simplifies comparison”.