Chapter 2, Section 5 Flashcards
Define Alternating Current.
An electric current that reverses direction periodically.
What is frequency?
The number of cycles of a periodic waveform occurring in a unit of time.
What is the unit of measure for AV frequency?
Hz.
What is the measure of a Hz?
The number of cycles per second in a waveform.
What is the resistance to current flow that can exist in an AC circuit?
Impedance.
What is a part of electrical impedance to AC when compared to electrical properties of capacitors and inductors?
Capacitors exhibit higher reactance at lower frequencies and inductors exhibit higher reactance at higher frequencies.
What is the opposition of current flow that is produced by a capacitor?
Capacitive reactance.
What is the phase relationship in a capacitance circuit between current and voltage?
The current leads the voltage by 90 degrees.
What is the formula for capacitive reactance?
The formula for capacitive reactance is Xc = 1/ (2(pi)(f)(C)), where Xc is capacitive reactance, f is frequency, and C is capacitance.
What is the current to voltage relationship in a purely inductive circuit?
The current lags behind the voltage by 90 degrees.
What is the formula for inductive reactance?
The formula for inductive reactance is XL = (2)(pi)(f)(L), where XL is inductive reactance, f is frequency, and L is inductance.
What is the effective value of power of an AV voltage when compared to a DC voltage?
Root mean square (RMS) value.
What is the measure between two or more signals that are not perfectly timed to each other?
Phase difference or phase shift.
What is the phantom power that is expanded in a circuit due to the energy expended by capacitors and inductors?
Reactive power.
What device converts an AC signal into a type of DC output?
A rectifier.
