C2:Electricity Flashcards
what is p.d
a measure of how much energy is transferred by each coulomb of electron
what is current
rate of flow of charge (how many coulombs pass every second)
how do you calculate p.d
energy transferred/charge flow
how do you calculate current
charge/time
what is resistance
a measure of how much a component resist the flow of charge
what is a resistor
heats up when current flows through it
how are current and pd similar
directly proportional
how do you calculate resistance
(ohms law)
p.d/current
why does a larger current mean an increase in resistance
more heat means more movement of ions which causes more collisions which cause a higher resistance
whats a diode
only lets a current flow in one direction
what are the rules for a series circuit
total p.d is shared between components
current is the same
resistance is added together
what are the rules for a parallel circuit
p.d of battery = p.d of components
current split between
total resistance is less than the resistance of the smallest resistor
what is a thermistor
as temperature increases resistance decreases
power =
p.d x current
what does the neutral wire do (blue)
takes the current back to the source and stays ay 0v