Electrical Principles Topic 2 Flashcards
Define Insulator
Little to no movement in electrons. Ex Wood, rubber, air
Define Conductor
Electrons are free to flow; conducts electricity
ex: Metal, water
Define semiconductor
At high temps its a conductor
At low temps its an insulator
ex: Silicon
Define superconductor
Perfect conductors with no resistance, at extremely low temperatures.
What is resistance, how is it measured?
A measure of how difficult it is for electricity to flow. It’s measured in ohms.
What are resistors?
They allow current to flow but provides resistance
What is a polygraph
Electrodes measure the salt in your sweat.
What is a switch
A device that allows the flow of electrons or stops the flow.
When a switch is open…
The circuit is interrupted and there is no flow
When a switch is closed…
The flow can pass through and continue the circuit
What is a rheostat
It allows the flow to change gradually
What is ohms law
As long as temperature stays the same, the resistance of a conductor stays constant and the current is directly proportional to the voltage applied
the 3 equations are:
IxR
V/R
V/I
2 types of resistors
Wire wound: The longer and thinner, the higher the resistance
Carbon-composite: By varying the composition and diameter different resistances are available
3 test meters
Voltmeter, Ammeters, Multimeters
