A 60-Hz 20-kVA 8000/240-V-rms transformer has the following equivalent-circuit parameters:
| Primary resistance |
R1 |
15Ω |
| Secondary resistance |
R2 |
0.02Ω |
| Primary leakage reactance |
X1 = ωL1 |
120Ω |
| Secondary leakage reactance |
X2 =ω L2 |
0.15Ω |
| Magnetizing reactance |
Xm = ωLm |
30kΩ |
| Core-loss resistance |
Rc |
200kΩ |
Find the percentage regulation and power efficiency for the transformer for a rated load having a lagging power factor of 0.8.