Chapter 3 Flashcards
Electric current
The flow of electrons (represented by the letter i and measured in amps (A)).
Ampere
Flow of one coulomb (6.25x10^18) of electrons per second
Voltage
The electromotive force that makes electrons move (represented by the letter e and measured in volts (V)).
Circuit
Any path through which current can flow.
Conventional current
Positive charge moving from a positive to a negative voltage.
Power
The rate at which electrical energy is used. P = e x i
Resistor
Opposes the flow of electrical current. Measured in Ohms.
Capacitor
Stores electrical energy in the electric field created by a voltage between two conducting surfaces called electrodes separated by an insulating dielectric. Capacitance is measured in farads. AC current passes through, but DC cannot.
Inductor
Stores energy in the magnetic field created by current flowing through a wire. Inductance is measured in henrys. Serves as a short circuit for DC currents, it resists AC current.
AC
Alternating current that regularly reverses direction.
DC
Direct current that flows in one direction all the time.
Impedance
The combination of resistance and reactance. Measured in Ohms and represented by the letter Z.
Reactance
Opposition to AC current flow because of capacitance or inductance. Measured in Ohms and represented by the letter X.
Resonance
When the reactance of an inductor balances the reactance of a capacitor at some given frequency.
Diode
A semiconductor that only allows current flow in one direction.
