Electromagnetism Flashcards
What metals are magnetic?
Iron, steel, nickel and cobalt.
What are some common non-magnetic materials?
Wood, glass, PVC, and aluminium.
What is the Law of Magnetism in summary?
-Opposites/unlike poles ATTRACT.
-Same/like poles REPEL.
What is a magnetic field?
The space around a magnet where the magnetic force acts.
When drawing or observing a magnetic field, where is the field the strongest?
Where there are many lines.
In what direction does current move, what is the name given to this?
North —> South
Positive —> Negative
This is called CONVENTIONAL CURRENT.
What is the fancy name for a coil in this topic?
A SOLENOID.
What is the ‘right hand grip rule’?
Wrap fingers around solenoid (coil) in direction of current; your thumb indicates the NORTH pole.
What is the advantage of an electromagnet over a permanent magnet?
You can turn it on and off.
What piece of equipment could you use to show the direction of the magnetic field around the electromagnet?
A plotting compass.
Does current move away or towards NORTH?
AWAY!
Does current move away or towards SOUTH?
TOWARDS!
What is the benefit of having a SOFT iron core?
It can be magnetised and de-magnetised.
What are the three factors affecting the strength of an electromagnet?
- The current
- The presence of a coil
- The number of turns on the coil
In the paper clip experiment, what would happen to the number of paper clips lifted if the iron nail was removed? Why?
It would decrease because the strength of the electromagnet decreases.
States 3 ways to DECREASE the strength of an electromagnet:
- Decrease the current
- Remove the core
- Decrease the number of turns on the coil
State three ways to INCREASE the strength of an electromagnet:
- Increase the current
- The presence of a core (soft iron)
- Increase the number of turns on the coil
An iron core is replaced by a wooden rod. What effect does this have on the magnetic field?
It decreases/weakens the strength of the magnetic field.
