Question 16: AC fundamentals

Question

A power transmission line feeds input power at 2200 V to a step-down transformer with its primary windings having 2000 turns. The output power is delivered at 220 V by the transformer. If the current in the primary of the transformer is 2 A and its efficiency is $80 \%$, the output current would be:

Accepted Answer

Compute the input power
$$P_{m in}=V_p\,I_p=2200\;	ext V	imes2\;	ext A=4400\;	ext W$$
Account for the transformerÃ¢ÂÂs efficiency
$$P_{m out}=\eta\,P_{m in}=0.80	imes4400\;	ext W=3520\;	ext W$$
Find the output current
$$I_{m out}=\frac{P_{m out}}{V_s}=\frac{3520\;	ext W}{220\;	ext V}=16\;	ext A$$
Answer: 16 A (Option C)

Answer

32 A

Answer

8 A

Answer

16 A

Answer

4 A

AC fundamentals

A power transmission line feeds input power at 2200 V to a step-down transformer with its primary windings having 2000 turns. The output power is delivered at 220 V by the transformer. If the current in the primary of the transformer is 2 A and its efficiency is 80 \%, the output current would be:

Choose the correct answer: