Lesson 9 AC Circuits

The potential difference and the current both change direction at a regular rate in ___ current.

• alternating

• direct

• electric

• electromagnetic

In the United States and Canada, the standard alternating rate for electric power is ___ Hz.

• 40

• 50

• 60

• 120

Alternating current is changed from one combination of potential difference and current to another by a(n)

• generator

• alternator

• capacitor

• transformer

In making calculations involving alternating current, you should use the ___ value.

• highest

• effective

• constant

• instantaneous

How many electrical degrees are in one complete electrical cycle?

• 90

• 180

• 270

• 360

Resistive AC circuits consist mainly of

• capacitors

• inductors

• resistors

• transistors

In addition to opposing a change in current, a coil

• delays the change

• hastens the change

• decreases the change

• increases the change

Which of the following is NOT a factor in the inductance of a coil?

• number of turns of wire

• size and shape of the coil

• material in the coil's core

• potential difference in the coil

The total opposition to the flow of current in an AC circuit is called

• inductive reactance

• capacitive reactance

• reistance

• impedance

A difference in phase between the current and the potential difference is commonly called

• phase angle

• phase difference

• AC difference

• lead or lag