chapter 5 final exam

For ac circuits, the ac _____ of a conductor must be taken into consideration.

(All of these) eddy currents skin effect resistance

In a purely inductive circuit, the CEMF waveform is _____ out-of-phase with the applied voltage waveform.

180 degrees

The waveform of the CEMF is ______ out-of-phase with the applied voltage

180 degrees

The induced voltage in a conductor carrying alternating current opposes the change in current flowing through the conductor. The induced voltage that opposes the current flow is called _____

All of these

If you measure voltage and current in an inductive or capacitive circuit and then multiply them together, you obtain the circuit's ______

Apparent power

A half-wave rectifier can be used to convert ac voltage into dc voltage to continuously charge a capacitor

False

AC inductive or capacitive reactive loads cause the voltage and current to be in-phase with each other.

False

Because apparent power (VA) is greater than true power (W), more loads can be placed on a circuit, so fewer circuits and panels, and smaller transformers might be required. True or false?

False

The true power of an ac circuit equals the volts times the amperes.

False

The total opposition to current flow in an AC circuit is known as ____ and is measured in ohms

Impedance

In a purely resistive ac circuit, the current and voltage are ______. This means that they both reach their zero and peak value at the same time

In-phase

The movement of electrons caused by an external magnetic field is called "_____ current", and the associated potential that is established is called "_____ voltage".

Induced

In dc circuits, the only property that affects voltage and current flow is ______.

Resistance

The expanding and collapsing magnetic field within the conductor induces a voltage in the conductors (CEMF) that repels the flowing electrons toward the surface of the conductor. This is called "_____".

Skin effect

Efficiency describes how much input energy is used for its intended purpose.

True

Even when power is removed from the circuit, capacitors can store large amounts of energy for a long period of time. They can discharge and arc if inadvertently shorted or grounded out.

True

The magnitude of self-induced voltage within a winding is directly proportional to the current flow, the winding, and the frequency at which magnetic fields cut through the winding

True

The movement of electrons themselves does not produce any useful work. It's the effects that the moving electrons have on the loads they flow through that are important

True

When alternating current increases, the polarity of the CEMF within the conductor tries to prevent the current from increasing.

True

When describing the relationship between voltage and current, the reference waveform is always _____.

Voltage

The opposition offered to the flow of alternating current by a capacitor is called "capacitive reactance", which is expressed in ohms and abbreviated _______

Xc

Self induced voltage opposes the change in current flowing in the conductor. This is called "inductive reactance" and abbreviated _____

Xl

The abbreviation for impedance is ______

Z

Self induced voltage is 180 degrees out of phase with the _____. When the applied voltage is at its maximum in one direction, the induced voltage is at its maximum in the opposite direction.

applied voltage

A nonsinusoidal waveform is created when _____ loads distort the voltage and current sine wave.

nonlinear

As the alternating current through a conductor increases, an expanding and collapsing electromagnetic field through the conductor induces a voltage within the conductor. This is known as "_____ voltage."

self-induced

The peak value is equal to the effective value _____.

times 1.41