Magnetism and Electromagnetism Flashcards
How do like poles of a magnet interact?
They repel each other.
How do unlike poles of a magnet interact?
They attract each other.
What is the area of force around a magnet?
The magnetic field.
What is a permanent magnet?
A magnet with its own magnetic field (nickel, iron, and cobalt).
What is an induced magnet?
A magnet with a temporary magnetic field when placed in another magnetic field.
What is an electromagnet?
It has a magnetic field as the result of an electric current running through a wire (conductor), and it can be turned on or off with a switch.
In what direction do magnetic fields run?
North to South.
What three ways can increase the magnetic field around an electromagnet?
Increasing the current, increasing the number of coils and adding a soft, iron core.
How do magnetic compasses work?
- The direction of the field at any point is the direction of the force on North pole.
- The field lines run from a north seeking pole to a south seeking pole of a magnet.
- The strength of the field is shown by how close the lines are. 4. Points along field lines of the Earth is evidence the Earth must be magnetic.
What is the motor effect?
When a current flows through a wire, a magnetic field is produced around the wire. Shaping the wire into a soleniod (coil) in uniform fields increases the strength of the magnetic field. When the wire is placed inside a magnetic field, a force is exerted on the wire.
What is Flemming’s Left Hand rule?
If a wire with a current flowing through it is placed in a magnetic field (between the poles of a magnet), it experiences a force.
Which fingers depict which part of Flemming’s Left Hand rule?
Thumb = Force/movement.
Index = Magnetism (N to S).
Middle = Current (+ to -).
How can the force be increased in Flemming’s Left Hand rule?
Increase the number of coils. Increase the length of the wires in the magnetic field. Increase the magnetic field strength. Increase the current in the wire/coils.
How can an electric motor produce a turning effect?
A coil of wire carrying a current in a magnetic field experiences a force that tends to make it rotate.
