Magnetism and electromagnetism

Magnetic forces are (contact/non-contact) forces

Non-contact

Name the 4 magnetic materials.

(Immy Stole Nicky’s Coat)

Iron, steel, nickel, cobalt

True or false: a permanent magnet produces its own magnetic field

True

The magnetic field of a permanent magnetic (can/can’t) be turned off

Can’t

Which type of magnet can only become a magnet when it’s placed in a magnetic field?

An induced magnet

True or false: induced magnets are only attracted by other magnets not repelled

True

When a current flows in a wire, it creates a circular ___ ___ around the wire

Magnetic field

What is the name of a coil of wire that can carry an electrical current?

A solenoid

The shape of the magnetic field for a solenoid is very similar to the magnetic field of a ___ ___

Bar magnet

What is the name of a solenoid with an iron core?

An electromagnet

What is the setup below an example of?

An electromagnet

What occurs when a wire carrying a current interacts with another magnetic field, causing a force that pushes the wire a right angles?

The motor effect

Give the name and symbol of the units for magnetic flux density

Tesla, T

In Flemming’s left hand rule, what does the thumb represent?

The direction

In Flemming’s left hand rule, what does the forefinger represent?

The magnetic field lines

In Flemming’s left hand rule, what does the second finger represent?

The current

The ___ ___ is used in the loudspeakers in headphones

Motor effect

When there is a current in the coil, it creates an ____ field which interacts with the ____ magnet, therefore generating a force that pushes the cone outwards

Electromagnetic, permanent

The cone of the loudspeaker vibrates in and out through the use of an ____ current

Alternating

A step-up transformer ___ the voltage

Increases

A step-down transformer ___ the voltage

Decreases

Does the diagram show a step-up or a step-down transformer?

A step-down transformer

In a transformer, the primary coil and secondary coil are wrapped around an __ ___

Iron core

True or false: mains electricity uses an alternating current

True

In the generator effect, using stronger magnets leads to a ___ magnetic field which leads to a (bigger/smaller) potential difference

Stronger, bigger

In the generator effect, moving the wire or the magnets more quickly will change the magnetic field faster and lead to a (bigger/smaller) potential difference

Bigger

The more ___ on a coil, the bigger the potential difference

Turns

When a wire experiences a change in magnetic field, a potential difference will be ___ across the wire

Induced

Dynamos produce ___ current

Direct

Alternators produce ___ current

Alternating

In an alternator, the slip rings and brushes means that the contacts (do/don’t) swap every half turn

Don’t

In a dynamo, the split ring commutator means that the contacts (do/don’t) swap every half turn

Do