Current, PD, and Resistance Flashcards
what is current?
the flow of electrical charge carried by electrons
measured in Ampere (A)
what is potential difference?
how much electrical work is done by a cell
measured in Volts (V)
what is charge?
the amount of electricity travelling in a circuit
measured in Coulombs (C)
what is resistance?
a measurement of how much current flow is reduced
what are the rules of resistance?
- the higher the resistance, the more difficult it is for current to flow
- increase in resistance, reduces current
- increase in voltage, increases current
how does a thermistor affect resistance?
resistance decreases as temperature increases
how does an LDR affect resistance?
resistance decreases as light increases
Ohmic conductor graph
at a constant temperature, current is directly proportional to the PD across the resistor
Filament lamp graph
as current increases, the resistance increases
the temperature increases as current flows
Diode graph
current flows when PD flows forward but there is very high resistance in reverse
