The correct answer is: B. per unit impedance
Explanation:
The per unit impedance of a transformer is a measure of its impedance relative to its rated voltage and current. It is calculated by dividing the transformer’s impedance by its rated voltage and current.
When two transformers are operating in parallel, the transformer with the lower per unit impedance will take on a larger share of the load. This is because the transformer with the lower per unit impedance has a lower impedance, and therefore a lower voltage drop. This means that more current will flow through the transformer with the lower per unit impedance, and it will take on a larger share of the load.
The other options are incorrect because they do not affect the way that transformers share a load.
- Leakage reactance is the reactance of the transformer’s windings. It does not affect the way that transformers share a load.
- Efficiency is the ratio of the transformer’s output power to its input power. It does not affect the way that transformers share a load.
- Ratings are the transformer’s rated voltage, current, and power. They do not affect the way that transformers share a load.