Question

that pu impedance referred to either side effect single phase transformer same ​

Answer 1

Answer:

A per-unit system provides units for power, voltage, current, impedance, and admittance. ... For example, the base power might be the rated power of a transformer, or perhaps an arbitrarily selected power which makes power quantities in the system more convenient. The base voltage might be the nominal voltage of a bus.

Answer 2

Answer:

your answer is in the above attachment