2

• how does the current flow

  negative to positive
• the current is the flow of electric charge
• the current carries electrical energy
• when electrons return to the positive terminal they are carrying 


  Less energy than before
• what is current measured in

  amps
• how do you measure current

  ammeter
• what is electric current

  flow of electric charge
• in a series circuit current is the same all around
• in a series circuit current is the ---- all around

  same
• in a parallel circuit the current does what

  splits
• the current in the branches adds up to the total current leaving the cell
• what is PD measured in

  volts
• what is the potential difference

  amount of energy transferred per coulomb of charge
• what do we measure PD with

  a voltmeter
• in a series circuit the total PD is shared between 2 components
• for components connected in parallel the PD across each component is the same
• in parallel circuits the PD around each component is

  the same
• what is a battery

  2 or more cells
• what is charge measured in

  coulombs C
• the size of the current is the rate of flow of electrical charge
• q = I x T
• charge = current x time
• energy transferred = charge x potential difference
• what does the resistance tell us

  the PD required to drive a current through a component
• v = I x R
• when electrons collide with atoms in the metal the electrical energy is transferred to other forms
• current through a resistor is directly proportional to the PD
• what is an ohmic conductor

  where the resistance does not change when we increase the current , resistance is only constant if temp is constant
• what do resistors do

  control the PD around other components
• why does temp cause higher resistance

  the atoms will vibrate more and the electrons are more likely to collide with them
• key features of a series circuit

  • All components are attached in a row.
  • The current is the same everywhere in the circuit.
  • The voltage across each component is different.
  • The sum of the voltages across each component is the total voltage.
• The total resistance of components in series is the sum of the resistance of each component. 
• the total resistance of two resistors in parallel is always less than the resistance of the smallest individual resistor.
• In a series circuit:

  • Current is the same at all points of the circuit.
  • The total potential difference of the power supply is shared between the components.
• In a parallel circuit:

  • The current is split between the branches.
  • The potential difference across each parallel-connected component is the same.
• resistors in series add togther
• when 2 resistors are in ------- we have two more pathways for the ------ to take which causes a ------- total current

  parallel current higher
• in dark resistance the ldr has a

  high resistance
• the resistance of a thermistor decreases if the temp increases
• when the temp is low the thermistors resistance is

  high