Electricity Flashcards
What is electricity?
presence or flow of charged particles
what is current?
flow of electrons from positive to negative
what is potential difference?
driving force of charge.
without it there is no current in the circuit. eg. cells + batteries
what is a cell?
supplies electricity (source of potential difference)
what is a battery?
two or more cells joined together
open + closed switch?
allows current to flow or not
filament lamp (bulb)?
converts the electrical energy to light energy
ammeter?
measures current in amps (a)
voltmeter?
measures potential difference in volts (v)
resistor?
reduces current flow. resistance remains the same. measured in ohms (Ω)
variable resistor?
reduces current flow but can change resistance. increase/decrease
fuse?
safety device that melts to break the circuit if current exceeds limit
thermistor?
resistor that depends on temprature. high temp = low resistance low temp = high resistance
LDR (light dependent resistor)?
resistor that depends on light intensity. high light intensity = low resistance low light intensity = high resistance
Diode?
makes sure current flows in one direction
LED (light emitting diode)
diode that emits light when current passes through it
formula for charge?
charge (C) = time (s) x current (a)
formula for potential difference?
potential difference (v) = current (a) x resistance (Ω)
features of a series circuit?
components in a line, forming a loop
remove/disconnect one component circuit broken
very few thing connected this way
features of a parallel circuit?
components joined by multiple branches
one component disconnected little effect on circuit because current can flow
Which component does this graphs show?
filament lamp
which component does this graph show?
diode
which component does this graph show?
LDR (light dependent resistor)
which component does this graph show?
thermistor
what does this show?
resistors at constant temperatures
