What Are Electric Fields?  An electric field is the area around a charge (either positive or negative) that is used to show electrical forces generated by that charge  Electric fields are shown as arrows originating with the charge  The direction of the arrow is given by what a positive test charge would do if dropped within the electric field of the charge

Pictures of Electric Fields

How To Calculate Electric Field Strength  Electric field strength (E) can be calculated with the equation:  E = F/q  E: Electric Field (N/C)  F: Force felt by the charge (from Coulomb’s Law)  q: Charge of the object

Magnetism and Electric Fields  Electricity and Magnetism are extremely closely related. So much so that they often follow the same equations.  Magnetic field lines follow the same pattern as electric fields  Before we get into “B Fields”, we need to first understand the magnet…

The Simple Bar Magnet  All magnets are made of two halves, or “poles”: north and south  North and south attract each other, just like positive and negative particles!  A north and a south can never be separated: if you break a magnet in half you will always have a north and a south, all the way down to a microscopic level!

How Do Magnetic Field Lines Look?  Magnetic Field lines, called “B Field lines, look identical to electric field lines.  The north pole of the magnet acts as a positive charge, and the south acts as a negative

What Happens When We Put Magnets Together?

Earth and Magnets  The earth has its own magnetic field, generated by its rotation.  The North Pole (geographic north) of the earth acts as a south pole magnet (magnetic south), and the South Pole (geographic south) of the earth acts as a north pole magnet (magnetic north).  This explains why the north needle on a compass is attracted to the North Pole!

Video  Electric Field Video Electric Field Video  Electric Field Problem Walkthrough Video Electric Field Problem Walkthrough Video

Simulations  Electric Field Hockey Electric Field Hockey  B Field Simulator B Field Simulator

Picture Credits  Slide 3: downloadanswer.com  Slide 4: facstaff.gpc.edu  Slide 4: mcat-review.org  Slide 7: newsouthwales.inetgiant.com.au  Slide 7:scienceblogs.com  Slide 8: facstaff.gpc.edu  Slide 9: ehow.com  Slide 9: sciencephoto.com  Slide 11: tigon2008.multiply.com