question_answer 38)

  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 such that  

Answer:

  (a,d)The line that draws power supply to our house from street supplies alternating current, whose average value/mean value over a cycle is zero. As the line has some resistance  therefore, voltage and current differ in phase such that Choices (a) and (d) are correct.