electromagnetism Flashcards
(10 cards)
What is an electric field?
The force field created by any charged particle or object.
The fields point from positive to negative representing repulsion of positive charges and attraction to negative charges of a positive test charge.
What is a magnetic field?
The force field created by a magnet or any moving charge.
The fields point from North to South. Opposites attract with magnets.
What does the Right Hand Rule for Current indicate?
A method to determine the direction of magnetic fields relative to current and moving positive particles.
Be careful of variations in how this rule is taught.
Define a magnet.
An object that creates a magnetic field.
Created by unpaired electrons causing atoms to be magnetic, which then join to create magnetic material.
What is an electromagnet?
A temporary magnet created by using coiled wire to create a directed magnetic field.
What are ferromagnetic materials?
Materials that can temporarily realign their domains to attract to a nearby magnet.
What is electromagnetic induction?
A loop of wire with a changing magnetic field passing through the loop will have a current induced in it.
More loops result in more current.
What is the function of transformers?
Transform the voltage from one wire loop to another.
The changing voltage changes the current as power must stay constant.
What do generators do?
Transform mechanical energy into electric energy.
Usually works by spinning a wire loop in a magnetic field.
What is the purpose of motors?
Transform electric energy into mechanical energy.
Usually works by providing electric current through a wire loop that is in a magnetic field, causing it to spin.
