Senca - Magnetism Flashcards
What is magnetism ? (Non contact force)
Magnetism describes the ability of magnets to attract (pull towards) and repel (push away) other magnets without touching them.
Magnets have a north pole (N) and south pole (S).
If two magnets are close enough to each other, then the south pole of one magnet will attract the north pole of the other magnet, or like poles will repel.
What are the only metals capable of being magnets ?
Iron, nickel and cobalt are the only pure metals that can be turned into a magnet. These metals are “magnetic materials”. (Also steel but steel is an alloy)
Properties of a magnetic material near a magnet and away.
-magnetic materials, like iron, are attracted to a magnet if they are close enough to the magnet. But are no different when not near a magnet from other metals to a certain extent.
Why are permanent magnets always magnetic ?
Permanent magnets are always magnetic, even when they are not near other magnets.They produce their own magnetic field.
Why can’t a magnetic material be repelled by a magnet ?
Magnetic materials can be attracted by a magnet, but can’t be repelled by a magnet.
Only two magnets can repel each other.
Non-magnetic materials will never be attracted to magnets.
Define induced magnetism
Induced magnets are magnetic materials that become magnets when they are in a magnetic field.When moved away from the permanent magnet, the magnetic material will stop being a magnet.This is called induced magnetism.
How are temporary poles created in the magnetic material ?
The permanent magnet induces (creates) temporary poles in the magnetic material and these align so that the magnetic material is attracted to the permanent magnet.
If the north pole of the magnet is next to the magnetic material, then a south pole will be induced in the part of the material closest to the magnet.
What is a magnetic field ?
Every magnet creates a magnetic field around itself.
A magnetic field is the area around a magnet where another magnet or magnetic material (iron, nickel, cobalt and steel) feels a force.
How can the strength of a magnets magnetic field be determined ?
The strength of a magnetic field depends on the distance from the magnet. The magnetic field is strongest at the magnet’s poles.
How can the strength of a magnets magnetic field be determined ?
The strength of a magnetic field depends on the distance from the magnet. The magnetic field is strongest at the magnet’s poles.
How can we prove the earth’s core is magnetic using a magnetic compass ?
A magnetic compass contains a small bar magnet. The needle of the compass points in the direction of the Earth’s magnetic field. This shows that the Earth’s core is magnetic.
How can we determine the strength of a magnetic field using a magnetic compass ?
The strength of the magnetic field at any point is indicated by the density of the field lines at that point.
Which way do the arrows on a magnetic compass always point ?
The arrows on magnetic field lines show the direction of a magnetic field. The arrows always point from the north pole of the magnet to the south pole.
What is the earth’s north pole actually defined as if a magnetetic compass always points north ?
This means that the geographic N-pole of the Earth is really a magnetic south pole, and the geographic S-pole of the Earth is really a magnetic north pole
Why can we determine that the earth’s core behaves like a bar magnet ?
If a compass is mounted vertically (a dipping compass) it shows that the Earth’s magnetic field enters the Earth at different angles in different places.
