Khan Academy
Khan Academy: Magnetic Force Between Two Currents Going in the Same Direction
Sal Khan shows how to determine the magnetic force between two currents going in the same direction. [10:59]
Science Friday Initiative
Science Friday: The Poles, They Are a Changin'
A Florida airport recently had to close its main runway to repaint directional signs, due to the changing location of magnetic north. We'll talk about the planet's magnetic field.
Khan Academy
Khan Academy: New Topic: Earth's Magnetic Field (How to Measure)
A demonstration of an experiment that asks the question, how can we describe the strength of the Earth's magnetic field using a magnet and a compass? What does this tell us? [1:17]
Khan Academy
Khan Academy: Inverse Cube Law (Method of Oscillation)
In this video, we compare the speed of compass oscillation vs. distance from a magnet. What kind of relationship do we observe. Is it linear? [2:08]
Khan Academy
Khan Academy: Inverse Cube Law (Deflection Method)
Watch an attempt to measure the change in the force of a magnet over a distance using the deflection of a compass. What is wrong with this approach? [1:47]
Khan Academy
Khan Academy: Earth's Magnetic Field (How to Measure)
How can we describe the strength of the Earth's magnetic field using a magnet and a compass? What does this tell us? Watch this demonstration to find out. [1:16]