P2 Electricity Flashcards
battery
two or more cells
current
measure of the flow of electrons around the circuit
current measured in
amps (A)
potential difference is the force driving the flow of
electrons
potential difference is provided by the
cell/battery
potential difference is measure in
Volts (V)
resistance is
everything that resists or opposes the flow of electrons around
resistance is measured in
Ohms (Ω)
current always flows from
positive terminal to negative terminal (even though it makes no sense)
what is ohm’s law
v = i x r
so long as resistance remains constant, potential difference and current are…
directly proportional
on current/potential difference graphs, the greater the resistance =
the less steep the gradient
temperature increase=
resistance increase
what does current increase result in on IV characteristics graph
current increase = increase heat = increase resistance = gradient less steep
diodes only allow current to flow
in one direction
diodes only show current when potential difference is
positive
what do diodes have in the opposite direction so that no current can flow?
really high resistance
charge is
a measure of the total current that flows within a certain period of time
charge is measured in
coulombs (C)
what happens if a component breaks in a series circuit?
the whole circuit stops working
how is the potential difference shared in a series circuit
across all components
in series circuits, Vtotal =
V1 + V2 + V3…
How is current shared in series circuits?
Current is the same everywhere
Current is measured by an
Ammeter
Ammeters are placed
in series
why can ammeters be placed anywhere in series circuit
because current is the same everywhere
in series circuits, total resistance =
sum of resistance of each component
voltage of single component =
current x resistance of component