SP12 Flashcards
Electromagneticism
What is the shape of magnetic fields around a wire?
It is a circular shape and the fields get stronger as you get closer to the wire and weaker away from the wire.
What happens to the direction of the magnetic field if the direction of the current changes?
It also changes.
Why is a circular shape magnetic field not very useful?
It’s circular shape means it has no poles: this means it can’t attract or repel things like a normal magnet thus cannot pick things up.
How are electromagnets made more useful?
Coiling up the wires combines the individual coil fields in a way that changes the shape.
What is a coil of wire with strong, uniform magnetic fields inside it called?
a solenoid.
What material is the core of a solenoid composed of and why?
Iron a s it makes the magnetic field stronger.
In what direction do magnetic field lines go on bar magnets?
from north to south.
What are a few examples of magnetic material?
Iron, cobalt, nickel, and steel.
What are induced magnets?
They are only magnetic (can only be the magnetic materials) when they’re in a permanent magnet’s field and they will always attract permanent magnets when they are near.
What direction does current flow in?
From the + (positive terminal) to the - (negative terminal).
