Question:
The line that draws power supply to your house from street has
(a) zero average current.
(b) 220 V average voltage.
(c) voltage and current out of phase by 90°.
(d) voltage and current possibly differing in phase φ such that |φ| < π/2.
Solution:
(a) zero average current.
(d) voltage and current possibly differing in phase φ such that |φ| < π/2.