Finding the direction of the magnetic field created by a current-carrying wire, with introduction to the right hand rule and a demo of a compass needle responding to the current through a wire.

Forces felt by two parallel current carrying wires, when the currents are in the same or in opposite directions. Includes a demonstration of these forces.

Finding the magnitude and direction of the magnetic field at the center of a loop of current, with comparison to a dipole field.

Using iron filings to view the magnetic field lines near a current-carrying wire and a loop of current.

Magnetic force on a current-carrying wire, with diagrams. Forces felt by wires with parallel and anti-parallel currents, with links to visualizations.

Table of important values and equations for resistors, capacitors, and inductors. Brief review of what happens in RC, RL, LC, and RLC circuits.

Statement; field of current-carrying wire and sheet; units; divergence of B and interpretation.

Derivation and statement; field of current-carrying cable, current sheet, solenoid, and toroid.

Two questions with answers and explanations.

Finding the magnetic field at points outside and in the plane of the ribbon.

Solution (PDF)

Explaining in words why parallel currents attract and antiparallel currents repel.

Solution (PDF)

Finding magnetic field using geometry from an arrangement of current-carrying wires.

Solution (PDF)

Finding field of one loop and force exerted on the other.

Solution (PDF)

Finding field of one loop and force exerted on the other.

Solution (PDF)

Applet showing the magnitude and direction of the magnetic field created by a small segment of current.

Applet demonstrating the method if integrating around a ring of current to find the magnetic field at a point above the ring.

Applet showing the magnitude and direction of the magnetic field at any point in or around a ring of current.

Video animation showing the magnetic field and behavior of two wires with current flowing in the same direction.

Video animation showing the magnetic field and behavior of two wires with current flowing in different directions.

Video animation showing the magnetic field and attraction of two coaxial wire loops with current flowing in the same direction.

Video animation showing the magnetic field and behavior of two coaxial wire loops with current flowing in different directions.

Video animation showing the magnetic field generated by a Helmholtz Coil when the two coils have current flowing in the same direction (magnetic dipole moments aligned).

Video animation showing the magnetic field generated by a Helmholtz Coil when the two coils have current flowing in different directions (magnetic dipole moments anti-aligned).

Interactive applet showing the magnetic field created by two rings with variable position, orientation, size, and current.

Interactive applet simulating the magnetic field and interactions of a current-carrying wire and a compass needle.