Chapter 18: Alternating Current

Question 1

What is period?

Answer 1

Period is the time taken for the completion of one cycle of the a.c.

Question 2

What is frequency?

Answer 2

Frequency is the number of complete cycles of the a.c. per unit time.

Question 3

What is angular frequency?

Answer 3

Angular frequency is the frequency in hertz multiplied by 2π radians per cycle.

Question 4

Define peak value

Answer 4

Peak value is the maximum value (in terms of magnitude) of the a.c. for one cycle.

Question 5

Define the root-mean-square value

Answer 5

The root-mean-square (r.m.s.) value of an alternating current is the value of the steady current that will dissipate heat at the same average rate as the alternating current in a resistive load.

Question 6

What’s an ideal transformer?

Answer 6

An ideal transformer is 100% efficient and has no power losses.