Series Circuit

• Series circuits have only one pathway for the electric current to flow through.
• • Components are connected in a line to form a series circuit
• • If one component is disconnected or removed, then the whole circuit will stop working. This isn't great
• The more cells in a circuit = the more potential difference there will be
• The total potential difference is shared across all components, this adds up to the source potential difference.

  V total = V1 + V2 +...
• Ammeters are connected in series
• • The current is always the same in all components
  • I 1 = I 2 =...
  • The current depends on the total potential difference and total resistance
  • I = V/R
• • The total resistance is the sum of all the components' resistances.

  R total = R1 + R2 +...

  • By adding a resistor in series means that the two resistors have to share the total potential difference.
  • The potential difference between each resistor is lower, so the current across it is lower (directly proportional). Current is the same everywhere in a series circuit, so the total current decreases when a resistor is added. This means that the total resistance increases

  
• Current and potential difference are directly proportional, so when one increases the other increases :)
• Current is inversely proportional to the resistance. So when the current decreases the resistance increases :)
• The more resistance a component has, the bigger share of the total potential difference (less potential difference can flow through the component)
• For the diagram here, calculate the current passing through the circuit:

  Total R = 5 ohms

  Total V = 20V

  I = V/R

  I = 20/5 = 4A