Finding the force a magnetic field exerts on a current-carrying wire, with a demonstration of a wire jumping in a strong magnetic field.

Finding the force on a moving charge in an electric and magnetic field. Finding the total force on a wire in a magnetic field.

Sample calculation of the force on a wire in a magnetic field from a demonstration earlier in the lecture.

Introduction to motor building contest. Discussion of force and torque on a current loop in a magnetic field, with example of current meters in cars.

Definition of a commutator, with further explanation of the motor contest.

Creating a motor from a current loop where the current is manually reversed after every 180° of rotation.

Overview of project in which students build a motor using little more than magnets, paper clips, a block of wood, and copper wire.

Magnetism from empirical evidence; Lorentz force on charge and wires; Electron trajectories; applications to modern physics; work done by B-fields.

Determines the magnetic force on an arbitrarily shaped current-carrying wire; example considering a semi-circular loop.

Calculates the torque on a square loop of current in a uniform magnetic field; also defines the magnetic dipole moment.

Determine the motion of a rolling current-carrying rod in a uniform magnetic field. Solution is included after problem.

Calculate the magnetic force required to counteract the force of gravity on a suspended current-carrying rod. Solution is included after problem.

Find the torque on a square current-carrying loop due to a uniform magnetic field, and find the value of current in equilibrium with gravity.

Find the current through a bar on an inclined plane in a uniform magnetic field, so that the forces balance.

Determine the force on a current-carrying wire that is skewed with respect to a magnetic field.

Determine the current density and power that are required to make a wire levitate in a magnetic field against the force of gravity.

Find the force on a rectangular current loop in the non-uniform magnetic field of a nearby finite current segment.

Identify the direction of the force on a current-carrying wire or loop in the field of a bar magnet.

Identify the direction of the force on a moving charged particle due to the magnetic field of another moving charged particle.

Characterize the behavior of magnetic dipoles in different magnetic field configurations.

Find the direction of the magnetic force when a current-carrying rod slides on rails in a uniform magnetic field.

5-part power problem; finding resistance, power, voltage conditions, and Lorentz force in power lines.

Solution (PDF)

Calculating magnetic field energy and self-inductance of a current-carrying wire.

Solution (PDF)

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

Solution (PDF)

Determining the cause of a CRT beam offset slightly to the right.

Solution (PDF)

Finding the torque on a current-carrying loop in a magnetic field.

Solution (PDF)

Finding field of one loop and force exerted on the other. Solution not included.

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

Solution (PDF)^#

Video animation showing a current-carrying wire moving into a uniform magnetic field, then being pushed back out because of the resulting force on the wire.

Video animation showing the magnetic field and behavior of a coil of wire suspended above a magnet, when the current through the wire is flowing in one direction and then the other.

Interactive applet showing the magnetic field and behavior of a coil of wire suspended above a magnet, when the magnitude and direction of the current through the coil can be changed in real time.