Magnetism Flashcards

Flashcards covering key concepts about magnetism, electromagnets, and their applications, based on the provided lecture notes.

Magnetic Field

The area around a magnet in which the effect of magnetism is felt.

Direction of Magnetic Field Lines

Always go from North to South, in curved lines towards the poles.

Circular Magnetic Field

When a current flows in a wire, it creates this around the wire.

Motor Components

Permanent magnet and a coil of wire. When current flows, you get an electromagnet, which interacts with the permanent magnet creating force, which then goes on to spin.

Earth's Magnetic Field

The core of the planet, which is mainly molten iron, creates a magnetic field as it spins around.

Magnetic material

Metal with iron in it will be attracted to a magnet, steel contains iron.

Ways to increase of the strength of an electromagnet

Increase the current, Increase the voltage, Add more coils of wire, Get a stronger core

Electromagnets in Scrapyards/ Recycling Centres

Used to lift and manoeuvre ferrous materials or extract them from scrap.

Iron Core Electromagnet

It loses its magnetism as soon as the switch is opened and the current is switched off.

Uses of Magnets

It detects the directions and poles of the earth's magnetic field, used in MRI machines, employed as fridge magnets, and utilized in furniture and household appliances

How to Create Your Own Magnet

Align the domains by stroking the object in the same orientation with a magnet.

Steel vs Iron as a Magnet Core

An iron core loses its magnetism quickly whereas a steel core makes a more permanent magnet

Magnetic Materials

Iron, Cobalt, Nickel and Steel

Uses of Electromagnets

Motors and generators, transformers, relays, electric bells and buzzers, loudspeakers and headphones.

Shape of magnetic field lines

Curved lines from North to South

Origin of Earth's magnetic field

Movement of molten iron and nickel in the Earth's outer core

How to Magnetize Iron

Stroke in the same direction to align domains

Demagnetizing Methods

Dropping, Heating, or Stroking randomly

Electromagnets in cranes

Electromagnet picks up, moves, and releases metals

Cutting a magnet in half

They become smaller magnets with own poles

A non-magnetic material

Aluminum