Direct Current (DC)
Circuit is traveling through the series in one direction.
Voltage
The amount of electromagnetic force (emf) available to move a current.
Current (I)
The progressive movement of electrons through a conductor.
Resistance (R)
In an electrical circuit, the opposition to electron movement or current flow. Its value is affected by many factors, including the dimensions and material of the conductors, the physical makeup and types of the components in the circuit, and temperature.
Series Circuits
A circuit in which components are connected in tandem or in a string providing only one path for current flow.
Parallel Circuits
A circuit with two or more paths for current flow where all components are connected between the same voltage points.
Series-Parallel Circuits
A circuit comprised of a combination of both series-connected and parallel connector components and/or subcircuits.
Ohm's Law
A mathematical statement describing the relationship among current, voltage, and resistance in electrical circuits.
Closed Circuit
A complete, unbroken path through which electrical current flows whenever voltage is applied to that circuit.
Open Circuit
Has a break in the path of current flow. This break may be a desired (designed) break or an undesired (unplanned) break.
Alternating Current (AC)
Voltage continually varies in magnitude, and periodically varies polarity.
Cycle
A complete series of values of a periodic quantity that recur over time.
Frequency (Ć’)
The number of cycles occurring in a unit of time. The number of cycles per second.
Resonance
A special circuit condition existing when opposite types of reactances in a circuit are equal and have cancelling effects.
Sinusoidal Waves (Sine Waves)
A wave or waveform expressed in terms of the sine function relative to time.
Period (T)
The time required for one complete cycle.
Wavelength
The distance a given signal's energy travels in the time it takes for one cycle of that energy.
V(RMS)
The effective value is the most frequently used value related to AC
V(pp)
The total amplitude from the peak positive point to the peak negative point.
V(p)
The negative/positive amplitude (height) of one alternation of a sine wave (for voltage).
Reactance
The opposition a capacitor or inductor gives to alternating current or pulsating direct current.
Inductors (coils or chokes)
A passive electrical component that opposes sudden changes in current.
Inductive Reactance (XL)
The opposition an inductance gives to ac or pulsating current.
Impedance
The total opposition an ac circuit displays to current at a given frequency; results from both resistance and reactance.
Transformers
Devices that transfer energy from one circuit to another through electromagnetic (mutual) induction.
Capacitors
A device containing two or more conductors, separated by nonconductor(s). When charged, stores electrical energy in the form of an electrostatic field and blocks dc current.
Capacitive Reactance (Xc)
The opposition a capacitor gives to ac or pulsating dc current.
Time-constants (L/R)
The value of the inductance in henrys divided by the resistance
Inductance
The property of a circuit to oppose a change in current flow.
Capacitance
The ability to store electrical energy in the form of an electrostatic field.