Physics- electricity Flashcards
(26 cards)
what is an electric current?
a flow of electric charge
What’s current measured in?
Amps, A
what is charge measured in?
coulombs, C
what would the current be like in a single loop circuit?
the current will be the same everywhere
what does the size of the current tell you?
how fast the charge is flowing
what’s potential difference that same as?
voltage
what is potential difference?
the driving force that pushes charge around
what’s potential difference measured in?
volts, V
what is resistance?
anything that slows down the flow of charge
what is resistance measured in?
ohms
charge flow equation
Q=IT
current x time
potential difference equation
V=IR
Current x resistance
what are examples of ohmic conductors?
wires and resistors
which components have a changing resistance?
bulbs and diodes
how does the resistance of a LDR change?
when light intensity changes
bright light = low resistance
low light = high resistance
how does the resistance of a thermistor change?
decrease as temperature increases,
hot conditions = low resistance
cool conditions = high resistance
a series circuit is…
a circuit in which all parts are connected end to end to provide a single path of current.
which component always has to be in parallel?
voltmeters
what happens if you remove one component from a series circuit?
the circuit will break so all components will stop working
in series, potential difference is…
shared between components
v total = v1 + v2 + ….
in series circuit cell potential difference…
adds up
in a series circuit current is…
the same everywhere
in series circuit resistance…
adds up
parallel circuit
a closed circuit where every component is connected separately
