# The per unit impedance of a transformer is

The per unit impedance of a transformer is

### Right Answer is:

The same whether computed from primary or secondary side

#### SOLUTION

The Per Unit value of any quantity is defined as the ratio of actual value to the base value.

PU value = actual value/base value

__Per unit system in transformers:__

The** per-unit impedance of a transformer is the same whether computed from the primary or secondary side** so long as the voltage bases on the two sides are in the ratio of transformation (equivalent per phase ratio of a three-phase transformer which is the same as the ratio of line-to-line voltage rating).