Terminology Flashcards
Why is an alternating current waveform called a sine wave?
A waveform represents the current or voltage varying with the sine of the elapsed time
Metals that are easily magnetized
Ferromagnetic
Ie) Iron - this is a ferrous material
Metals that cannot be magnetized
Diamagnetic
Ie) copper, brass
Magnetic lines of force
Flux
The magnetic field formed around a conductor
Electromagnetic field
The base material of a coil
Core material, iron
The ability of a material to become magnetized
Permeability.
Resistance to magnetism
Reluctance.
Ie) Iron = low reluctance, becomes easily magnetized
Copper = high reluctance, does not become magnetized
Measure of a materials ability to retain magnets
Retentivity or Coercive Force
Term used to describe the total force producing a magnetic field
Magnetomotive Force (mmf)
Measure of charge
Coulomb
Ohms law for DC current
Current is directly proportional to the voltage, inversely proportional to the resistance.
What is a node?
A junction in a circuit
Electromagnetic Induction
When a conductor cuts through magnetic lines of flux a voltage is induced into the inductor
Lenz Law
An induced voltage or current opposes the motion that causes it.
Measurement of inductance
Henry
Cycle
One complete waveform of 360°
Frequency
The number of complete cycles that occur in 1 second
Peak Value or Amplitude
The measurement from zero to the highest value in the positive or negative position
True power
Watts
Loads that contain pure resistance
Resistive loads
If the current rises and falls at the same rate as voltage and reverses the direction of flow when the voltage reversed polarity, the current is what
In phase with the voltage
Skin effect
AC induced eddy currents, the eddy currents push the electrons outward (repel)
