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