Series & Parallel Resistance

12PHYS - Electricity

Finn Le Sueur

2024

Mahi Tuatahi

A circuit has current \(1.2A\) and voltage of \(12V\) and has a single bulb.

  1. Draw the circuit and indicate current and conventional current directions.
  2. How many Coulombs of electrical charge flow through a point in every second?
  3. How much energy is used by the bulb in 5 seconds?
  4. What is the resistance of the bulb?

Series Circuits

  • The current has only one path to flow around
  • The current is constant around the circuit
  • The voltage is shared between the components in the loop
Source

Parallel Circuits

  • The current has multiple paths to flow around
  • The current is shared between paths (like a river)
  • The voltage is shared between components on each separate path

Total Resistance in Circuits

  • When you add resistors in series, the total resistance increases
  • When you add resistors in parallel the total resistance decreases
    • Because there are more paths for the current to flow through (the pipe is bigger)

Calculating Resistance

In series we can use this equation:

\[ \begin{aligned} R_{T} &= R_{1} + R_{2} + R_{3} + ... \end{aligned} \]

In parallel we can use this equation:

\[ \begin{aligned} \frac{1}{R_{T}} &= \frac{1}{R_{1}} + \frac{1}{R_{2}} + \frac{1}{R_{3}} + ... \end{aligned} \]

Pātai Tahi

Find \(R_{T}\) for this group of resistors.

Pātai Rua

Find \(R_{T}\) for this group of resistors.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Calculate the values for each voltmeter, ammeter, as well as the total resistance of the circuit.

Series and Parallel Resistors

  • Collect a Series and Parallel Resistors sheet from the front.
  • Set up a station in a small group with a hardmat to protect the bench.
  • Complete Task 1-4.