Series & Parallel Circuits

• What are the 2 ways that a component can be connected in a circuit?

  Series (same loop) and Parallel (adjacent loop).
• Voltage is also known as potential difference.
• How does the potential difference across two components vary when connected in series and parallel?

  In a series circuit the total P.D is shared between each component. In a parallel circuit the P.D across each component is the same.
• If two resistors are connected in parallel, what can be said about their combined total resistance?

  Their total resistance is less than the smallest of the two individual resistances.
• If two resistors are connected in series, what can be said about their total resistance?

  Their total combined resistance is equal to the sum of the two individual resistances.
• Where must a voltmeter be placed in a circuit?

  In parallel with the component that is being measured.
• Give an equation relating potential difference with energy transferred and charge.

  Potential difference (V) = Energy transferred (J) / Charge (C)

  V=E/Q
• A volt can also be described as a joule per coulomb.
• What is an electric current?

  The rate of flow of charge.
• State the equation linking charge, current and time. Give the units for the quantities involved.

  Q=IT

  Charge (Coulombs), Current (Amperes), Time (Seconds)
• What can be said about the value of current at any point in a single closed loop?

  Current is the same at all points in a closed loop.
• What 2 factors does the current in a circuit depend on?

  Potential difference (V) and Resistance (R).
• What equation should be used to calculate potential difference if current and resistance are known? State the units for all 3 quantities.

  V=IR

  Potential difference (V), Current (A), Resistance
• What is an ammeter and where must it be connected in a circuit?

  An ammeter measures current. It is placed in series with the component it is required to measure.
• What happens when current reaches a junction in a circuit?

  Current is conserved; the total current remains the same and is split between the two branches.