ASVAB Electronics

Wires

Used to pass current from one part to another

cell

supplies electrical current

equals 1.5 volts

battery

is two or more cells

volts

measure the distance between two points

Amperes (amps)

measure the number of electrons that move past a specific point in 1 second

Ohms

measures resistance, including anything that could limit the flow of electrons

current

Occurs when electricity moves from one place to another

measured in amps and flows from negative to positive pole

conductors

allow electrons to move freely

watt

measures power at which electrical energy is consumed

one killowatt

equals 1,000 watts

one megawatt

equal to 1,000 kilowatts

semicondutors

have half-full valance shells which are neither good nor bad

insulators

full valance shells so electrons can’t move much

heat effect

develops when the current overcomes the resistance of the wire

direct current

comes from a battery

alternating current

it can change direction and voltage from higher to lower current when it encounters a transformer

hertz

a measure of frequency

frequency

the amount of times an alternating current changes direction per second

capacitance

the storage of energy

inductive reactance

is the resistance to change in the flow of current

diodes

allow electricity in only one direction. the electrical version of a valve.

reactification

making the change from ac to dc

transistor

a device used to amplify a signal

contains 3 terminals Emitter, Base, Collector

ground

a connection to the earth

transducer

converts energy from one form to another (motor,lighting lamp, heater, microphone,etc….)

inductor

a coil of wire that creates a magnetic field when current passes through

resistor

rated in ohms and have a color code

Black 0

brown 1

Red 2

Orange 3

yellow 4

green 5

blue 6

violet 7

gray 8

white 9

Amplifier

used to magnify power, current or voltage

Ohms law

current = Voltage/resistance