Magnetism Flashcards
Name 3 types of permanent magnets.
- Bar magnet
- Horseshoe magnet
- Ball magnet
What are the 3 magnetic elements?
- Iron (Fe)
- Nickel (Ni)
- Cobalt (Co)
What is an alloy?
An alloy is a mixture of metals.
What is Steel an alloy of?
Iron and Carbon.
What are the two magnetic poles that a magnet has?
North and South pole.
What would happen if you cut a magnet in half?
It would become two separate magnets, each with their own North and South poles.
What is the Law of Magnetism?
The Law of Magnetism states that like poles (N-N, S-S) repel, and unlike poles (N-S, S-N) attract.
What is a domain?
A domain is a region within in magnetic material that must be aligned to its other domains in order to become a magnet.
Name 2 ways to make a magnet.
- Stroking it with a magnet in the direction of its magnetic field
- Placing it near a strong magnet
What is the process of making a magnet called?
Magnetic Induction.
How can a magnet be broken? Name 3 ways.
- Heating it up
- Hammering it continuously
- Sending an alternating current (AC) through it
What is a magnetic field?
A magnetic field is the space surrounding a magnet where the effect of the magnet can be detected.
How can a magnetic fields direction be indicated?
With arrows.
From where to where on a magnet does a magnet current flow?
From North to South pole.
How can a compass be used to determine the direction of a magnet’s magnetic field?
A compass needle is a tiny magnet, therefore the pointer of the compass will always point to a magnet’s South pole, and away from a magnet’s North pole, indicating the magnetic field direction.
Is Earth a magnet?
Yes.
The Earth’s magnetic North pole is actually a _______ pole to a magnet.
South.
The Earth’s magnetic South pole is actually a _____ pole to a magnet.
North.
What is an electromagnet?
An electromagnet is a magnetic material that has become a temporary magnet because of an electric current flowing through it.
What components are needed to build an electromagnet?
Conducting wire
Battery/cell
Iron nail/magnetic material
What is created around a conducting wire when current flows through it?
A magnetic field.
What is a solenoid?
A solenoid is usually a copper wire with many circular turns/coils that carry a current. The current creates a magnetic field, similar to that of a bar magnet.
How can an electromagnet’s strength be increased? Name 3 ways.
- Increasing the amount of turns in the solenoid
- Increasing the current strength flowing through the solenoid
- By placing a soft iron core inside the solenoid - soft means it can easily be magnetised
Electromagnets can be turned ____ and ____. The ____ iron core becomes _____________ when there is no ______ flowing.
On. Off. Soft. Demagnetised. Current.
Give 2 examples of the uses of an electromagnet.
- Scrapyard - an electromagnet is used to pick up and move cars
- Doctors/medicine - an electromagnet is used to surgically remove metal from patients.
What is a relay switch?
A relay switch uses a small current in one circuit to active an electromagnet that closes a second circuit with a big current.
What is a reed switch?
A reed switch uses pieces of magnetic material (reeds) with a gap between them, all enclosed in a glass tube.
