physics

Permanent magnet

A magnet that stays magnetised without electricity.

Temporary magnet

A magnet that only becomes magnetic in a magnetic field or when you stroke it.

Magnetic domain

A region where atoms’ magnetic fields are aligned in the same direction.

Making a permanent magnet

Stroke metal in one direction or use a strong magnetic field to align domains.

Electromagnet requirements

Iron core, coil of wire, electric current.

Right-hand grip rule

A method to find magnetic field direction using your hand.

Compass method

A compass shows the direction of a magnetic field.

Dc motor

An electromagnet pulls a striker to ring a bell by breaking and remaking a circuit.

D.C motors

A device that converts electrical energy into movement using magnets and current.

How do D.C motors work?

A wire  in a circuit is passed through two magnets and is allowed to rotate

Make a DC motor stronger

Increase current, add more coils, use stronger magnets.

Battery

A device that converts chemical energy into electrical energy.

Two metals are needed in a battery, what are they called inside the battery?

electrodes 

What is the name of the liquid in the battery?

electrolyte

For a battery to work the two metals must be different from one another, how?

Different reactivity 

Cell

A single unit that provides electrical energy.

Battery (in circuits)

Two or more cells joined together.

Why battery metals must be different

They must have different reactivity to produce a voltage.

Conductor

A material that allows electric current to flow easily.

Insulator

A material that does not allow electric current to flow easily.

Current

The flow of electric charge (electrons).

Ammeter

Measures current in a circuit.

Unit of current

Amps (A).

Electricity flow

Electrons.

Voltage

The push (potential difference) that moves electrons.

Unit of voltage

Volts (V).

Voltmeter placement

Connected in parallel across a component.

Ammeter placement

Connected in series in a circuit.

Voltage in parallel circuit

The same across all branches.

Current in parallel circuit

Splits between branches.

Open switch

─o o─ (circuit broken, no current flows).

Closed switch

─o─o─ (complete circuit, current flows).

Lamp

─(X)─ (produces light when current flows).

Resistor

─[ ]─ (reduces current).

Variable resistor

─[↗]─ (can be adjusted to change resistance).

Cell

─| |─ (single power source).

Battery symbol

─| |─| |─(multiple cells joined together).

Ammeter symbol

─(A)─ (measures current).

Voltmeter symbol

What is this symbol ─(V)─

Motor symbol

─(M)─ (converts electrical energy into movement).

how to take away a magnetic domain from a permanent magnet?

Hit it hard on the table or melt it.

How do electric bells work?

Circuit with an electromagnet. When the circuit is turned on the armature is pulled over to the magnet and the bell is hit. When the armature has moved, the circuit is broken, so the electromagnet is no longer magnetic.