Open and short circuit tests

A 4 kVA 200/400 V single phase 50 Hz transformer has the following data on O. C. (open circuit) &
S. C. (short circuit) test:
O. C. Test: 200 V 0.8 A 70 W (Low Voltage side)
S. C. Test: 20 V 10 A 80 W (High Voltage side)
Find Full Load efficiency and regulation at pf 0.8. Find also the magnetizing component of No Load current.

Final Answer:

e =  1

Step-by-step explanation:

$$\begin{gathered} f=0.8 \\ {U}_1=200\text{V} \\ {I}_1=0.8\text{A} \\ {P}_1=70\text{W} \\ {U}_2=20\text{V} \\ {I}_2=10\text{A} \\ {P}_2=80\text{W} \\ {S}_1=U_1\cdot I_1=200\cdot 0.8=160\text{VA} \\ {S}_2=U_2\cdot I_2=20\cdot 10=200\text{VA} \\ e=1 \end{gathered}$$

Try another example