Electrical test Flashcards
Atom
Smallest particle of an element
Nucleus
Has protons and uncharged particles called neutrons
Atomic number
The number of protons a element has.
Ammeter
An electrical instrument used to measure current
Ampere
The unit of electral current
Atom
the smallest particle of an element
AWG
American Wire Gauge; a standardization based on wire diameter
Charge
can be - or +
Circuit
Has a source, a load, and an interconnecting current path
Conductance
The ability of a circuit to allow current. The unit is siemens (S)
Coulomb
The unit of electrical charge 6.25 x 10^18
Closed circuit
A circuit with a complete current path
Coulombs law
V=W/Q
Current
The rate of flow of charge (free electrons)
Current Source
A device that produces a constant current for a varying load
DMM
Digital multi meter; an electronic instrument that combines meters for measurement
Fuel cell
a device that converts electrochemical energy from an external source into dc voltage . the hydrogen fuel cell is the most common one
Fuse
a protective device that burns open when there is excessive current in circuit
Ground
The common or reference point in a circuit
Load
an element (resistor or other component) connected accross the output terminals of a circuit that draws current from the source and upon which work is done
Ohm
the unit of resistance
Ohmeter
An instrument for measuring resistance
Open circuit
Not a complete current path
Potentiometer
A three terminal variable resistor
Resistance opposition to current. The unit is the ohm
A rheostat
a two terminal variable resistor
Volt
the unit of voltage or electromotive force
Resistance of a wire depends on
Type of material, length of wire, cross sectional area
How to generate DC voltage
batteries,
solar cells,
generators (DC, AC)
power supply, thermocouples
Variable resistors
Potentiometer: to divide control voltage
Rheostat:to control current
Electrical current
The rate of flow charge
