Calculating the dot and cross products when vectors are presented in their x, y, and z (or i, j, and k) components. Created by Sal Khan.
Introduction to the cross product. Created by Sal Khan.
A little more intuition on the cross product. Created by Sal Khan.
Students will become familiar with the properties of magnets. They will design a data collection sheet to show where magnets are hidden in a closed box with their explanation of their findings. They will also design a game or activity using magnets and present their activity to the class.
Understanding the differences between the dot and cross products. Created by Sal Khan.
Sal shows that there will be a net torque on a loop of current in a wire. Sal shows that this net torque will cause the loop to rotate. Created by Sal Khan.
Sal shows that a commutator can be used in order to keep the loop of wire rotating in the magnetic field. Created by Sal Khan.
Sal finishes the explanation of how a commutator will allow a loop of wire to continue spinning in a magnetic field, thereby allowing it to work as an electric motor. Created by Sal Khan.
An emf induced by motion relative to a magnetic field is called a motional emf. This is represented by the equation emf = LvB, where L is length of the object moving at speed v relative to the strength of the magnetic field B.
This activity is a classroom and lab investigation of magnetism. Students gather results of experiments involving the forces of magnets. They use this data to develop their own experiments to test properties of magnets.
Play with a bar magnet and coils to learn about Faraday's law. Move a bar magnet near one or two coils to make a light bulb glow. View the magnetic field lines. A meter shows the direction and magnitude of the current. View the magnetic field lines or use a meter to show the direction and magnitude of the current. You can also play with electromagnets, generators and transformers!
Light a light bulb by waving a magnet. This demonstration of Faraday's Law shows you how to reduce your power bill at the expense of your grocery bill.
Light a light bulb by waving a magnet. This demonstration of Faraday's Law shows you how to reduce your power bill at the expense of your grocery bill.
How a current can be induced in a loop of wire by a change in magnetic flux.
Example calculating induced current based on change in flux.
How Faraday's Law is used to generate electricity in turbines.
Introduction and intuition for flux and magnetic flux.
Generate electricity with a bar magnet! Discover the physics behind the phenomena by exploring magnets and how you can use them to make a bulb light.
Sal determines the current and EMF induced in a wire pulled through a magnetic field. Created by Sal Khan.
An introduction to magnetism. Created by Sal Khan.