Magnetism - 16
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1
Which points of bar magnets have the strongest magnetic attraction?
A short distance from the ends
2
What are the magnetic materials?
Iron, Nickel, Cobalt & Steel
3
Is stainless steel a magnetic material?
No as stainless steel is an alloy of iron, nickel and chromium. The chromium prevents the iron and nickel atoms from aligning in a magnetic orientation, which is necessary for the material to be magnetic
4
How to test for a magnet?
By using the repulsion test
5
What is a magnetic field?
It is the region around a magnet in which magnetic force can be detected.
6
How to construct magnetic field patterns around a bar magnet?
7
How to construct magnetic field patterns between 2 unlike poles
8
How to construct magnetic field patterns between 2 like poles
9
What is induced magnetism?
It is when a non-magnetised material is brought near to (or touches) a magnet, the material itself will become a weak magnet.
10
Soft vs Hard magnetic material and example of 1 material of each type
They are easily magnetised and de-magnetised e.g. Iron vs hard to be magnetised and de-magnetised e.g. steel
11
To determine the north pole of a solenoid, which direction does current flow?
Positive to negative aka conventional current
12
What are some usecases of temporary magnets?
Junkyards, electric bells and magnetic relays
13
What are some usecases of permanent magnets?
Magnetic door catch, magnetic strips in refrigerator, moving coils in loudspeaker and galvonometer
14
What are the ways to increase the strength of an electromagnet?
Increasing current, increasing number of turns per unit length of the solenoid, placing a soft iron core within the solenoid to concentrate the magnetic field strength
15
How is the direction of current determined straight wires?
By using the right-hand grip rule and pointing your thumb either into or out of the page depending on whether it’s a cross or dot respectively
16
How is the magnetic field pattern of a solenoid determined?
By using the right-hand grip rule and curling your fingers in the direction of the current, the thumb will then point to the north pole of the solenoid
17
What are some applications of magnetic affect of current?
Electric bell, Magnetic relay, circuit breaker
18
How is the direction of force of motor effect determined?
Flehming’s Left Hand Rule where the direction of 2 of the things can be used to find the last one
19
Between 2 magnets, what direction does the magnetic field travel in?
North to South pole of the magnets
20
Why is there a force on the wire in this setup?
Due to the difference in magnetic field strengths at A and B, a force will act on the wire
21
When current in both wires flows in the same direction..
An attractive force is produced
22
When current in both wires flows in the opposite direction..
A repulsive force is produced