Electrical Symbols

Electricity - 10SCIE

Finn Le Sueur

2024

Akoranga 3 Mahi Tuatahi

Stella shuffles around her house wearing a pair of wool socks. She wants to shock one of her friends.

  1. Explain why she has to shuffle around the floor
  2. Explain why a shock will be produced

Whakatika / Answer

  1. Explain why she has to shuffle around the floor
    This applies friction between the socks and the floor. This will remove electrons (negative charge) from the socks, leaving them positively charged.
  2. Explain why a shock will be produced
    When there is an imbalance in charge (static electricity), the charges will want to balance out and become neutral. This often occurs as an electric shock.

Electrical Diagrams

  • A big part of Electricity is being able to draw and label diagrams. This helps us understand questions and is a key skill for the test.
  • We need to learn a series of common symbols that get used in diagrams.
Source

Symbols, Names and Uses

In your book, draw the symbol, write the name and the use (if applicable).

Wires: A straight line with right-angled corners that connects electrical components

Open Switch

A break in the circuit - stops the current from flowing.

Source

Closed Switch

Makes the circuit complete - allows the current to flow.

Source

Ammeter

Measures the flow of current in the circuit. Placed in the circuit in series.

Source

Voltmeter

Measures the amount of voltage used up by components in the circuit. Placed in the circuit in parallel.

Source

Battery

Provides energy to the circuit.

Source

Cell

Provides energy to the circuit.

Source

Diode

Only lets the current flow in one direction (the direction of the arrow).

Source

Fuse

Heats up and breaks when the current gets too high. Protects the circuit from electrical fires.

Source

Lamp

Creates light by using up energy.

Source

Motor

Uses energy to create rotational motion.

Source

Resistor

Reduces the current in the circuit by impeding flow of electrons.

Source

Variable Resistor

A resistor that can be changed to reduce the current more or less.

Source

Connecting Components in Series

Connecting in series means to put them in the same loop.

Source
  • The resistor and ammeter are in series because they are in the same loop.
  • Always place an ammeter in series. Placing it in parallel will break it.

Connecting Components in Parallel

Parallel components exist on separate loops of the circuit.

Source
  • The light bulbs and ammeter are in series, but the voltmeter is in parallel.
  • Always place a voltmeter in parallel because it measures the “different” in voltage between two points.

Pātai

  1. Neatly draw these circuits in your book.
  2. In pairs, decide whether each circuit is a parallel or series circuit.

Whakawai / Practise: Drawing Circuits

  1. A circuit with a battery, two bulbs in series.
  2. A circuit with a battery, two bulbs, an open switch and a resistor in series.
  3. A circuit with a battery, two bulbs in parallel, with a switch that can turn both lights on/off.
  4. A circuit with a battery, two bulbs in parallel, with a switch that can turn one bulb on/off.
  5. A circuit with a battery, three bulbs and a switch, where two bulbs can be controlled by the switch, and the third is always on.

Tākaro / Game

Kahoot!