Electrical Energy: Circuits, Conductors, and Safety Principles

Electrical Current

An electrical current is generated by electrons moving around a closed circuit.

Electrons

Electrons have an electrical charge that is negative.

Electrical Charge

Protons have a positive electrical charge. Electrons have a negative electrical charge.

Electrical Conductors

A material that allows electrical current to run through it (e.g. metal).

Electrical Insulators

A material that has a high resistance to electrons flowing through it (doesn't let the current pass through).

Voltage

A measure of the electrical potential difference between two points.

Current

The flow of electric charge, measured in amperes.

Resistance

A measure of the opposition to the flow of electric current, measured in ohms.

Ampere

The unit of electric current.

Volt

The unit of electric potential or voltage.

Circuit Components

Elements that make up an electrical circuit, such as resistors, capacitors, and inductors.

Series Circuit

A circuit in which the components are connected end-to-end, so that the current flows through each component in turn.

Parallel Circuit

A circuit in which the components are connected across common points or junctions, providing multiple paths for the current.

Static Electricity

The build-up of electric charge on the surface of objects, often resulting in a spark or shock.

Electric Shock

A sudden discharge of electricity through a part of the body.

Lightning

A natural electrical discharge of very short duration and high voltage between a cloud and the ground.

Current Electricity

Electricity that flows in a circuit, as opposed to static electricity.

Energy Source

A source that provides electrical energy, such as batteries or generators.

Circuit Diagram

A graphical representation of an electrical circuit, showing the components and their connections.

Closed Circuit

A complete electrical circuit through which current can flow.

Open Circuit

A circuit that is not complete, preventing current from flowing.

Brightness in Circuits

The effect of placing a light bulb in series or parallel on its brightness, with parallel circuits typically resulting in brighter bulbs.

INSULATORS

Some materials (glass, ceramic, plastics) are so resistant they block electrical current altogether.

ELECTROCUTION & RUBBER BOOTS

If you become part of a closed electrical circuit that conducts an electrical current, you can become electrocuted. Rubber boots are insulators, preventing a circuit from forming.

ELECTRIC SHOCKS

When an electrical signal passes through you, it activates your nerves (electrical signal!) and causes your muscles to tense up immediately & intensely. It causes your flesh to overheat and can cause burns.

AMPERES

The frequency of electron movement is called the amperage. It measures how many electrons (or how much charge) passes a particular spot in the wire per second. It is measured in Amperes / Amps (A) using an ammeter.

FACTORS AFFECTING RESISTANCE

Resistance depends on the material (metals have low resistance, while materials like rubber have a high resistance) and the shape of the material (longer metal wire = more atoms to get past = lower resistance; thinner wire = less room to manoeuvre around atoms = greater resistance).

MEASURING ELECTRICITY (DEVICES)

We can use particular devices ('meters') to measure these three things in a circuit: Ammeters measure amperage. Voltmeters measure voltage. Multimeters measure amperage, voltage, or resistance.

COMPARING CIRCUITS - PARALLEL VS SERIES

Understand the structure and function of circuit components: Wires, resistors, insulators and measuring devices. Distinguish between series and parallel circuits.

Supply Voltage

How much push a battery can provide to electrons in the circuit, measured in volts.

Cell

A unit with two electrodes, one that gives and one that takes electrons, separated unless connected to a circuit.

Battery

A device made up of a number of cells stuck together.

Wire

A conductive material made of metal that provides a path for electrons to move through.

Resistor

A component placed in circuits to decrease voltage and prevent overload.

Electrical Components

Devices like motors and lightbulbs that use kinetic energy of electrons to create light, heat, sound, or movement.

Short Circuit

When electricity takes an unintended path with very low resistance, potentially causing overheating and damage.

Active Wire

The brown wire that carries electrical currents to an appliance.

Neutral Wire

The blue wire that carries electrical currents away from an appliance.

Earth Wire

The wire that carries errant electrical currents to the ground, away from you.

Fuse

A safety device that melts when too much current flows through it, breaking the circuit.

Circuit Breaker

A device that monitors current flow in and out of a circuit, breaking the circuit to prevent current leakage.

Electrical Safety

Practices and devices like fuses and circuit breakers that contribute to safe electrical usage.

Kinetic Energy

The energy of electrons used by electrical components to create various forms of energy.

Voltage Drop

The decrease in voltage across a component in a circuit due to its resistance.

Device Blow-Out

When a device fails, affecting only its own branch in a parallel circuit.

Current Leakage

When current flows outside its intended path, potentially causing hazards.

240V AC

The supply voltage from power sockets at home, coming from the power grid.

Safety Switch

A device that monitors current flow and breaks the circuit in case of discrepancies.