Practice describing magnetic fields, forces on moving charges, and the principles of electromagnetic induction.
Read each problem carefully. Show your reasoning and include units when needed.
Exploring how magnets, currents, and changing fields interact
Physics - Grade 9-12
- 1
Describe the magnetic field around a straight wire carrying an electric current. Include the shape and direction of the field lines.
- 2
A student moves the north pole of a bar magnet toward a coil of wire. Explain what happens to the magnetic flux through the coil and whether an induced current is produced.
- 3
State Faraday's law of electromagnetic induction in words.
- 4
A coil has 200 turns. The magnetic flux through each turn changes from 0.10 weber to 0.04 weber in 0.20 second. Find the magnitude of the induced electromotive force.
- 5
Explain Lenz's law and how it determines the direction of induced current.
- 6
A charged particle moves perpendicular to a uniform magnetic field. What kind of path does it follow, and why?
- 7
Write the equation for the magnetic force on a moving charge and define each variable.
- 8
A wire 0.50 meter long carries a current of 3.0 ampere perpendicular to a magnetic field of 0.40 tesla. Calculate the magnetic force on the wire.
- 9
Compare a permanent magnet and an electromagnet. Give one advantage of an electromagnet.
- 10
A loop of wire is stationary in a constant magnetic field. Will an induced electromotive force be produced? Explain.
- 11
List two ways to increase the induced electromotive force in a coil.
- 12
Explain how a simple electric generator uses electromagnetic induction to produce electrical energy.