12.1 The Biot-Savart Law
For calculating magnetic fields, what are the advantages and disadvantages of the Biot-Savart law?
Describe the magnetic field due to the current in two wires connected to the two terminals of a source of emf and twisted tightly around each other.
How can you decide if a wire is infinite?
Identical currents are carried in two circular loops; however, one loop has twice the diameter as the other loop. Compare the magnetic fields created by the loops at the center of each loop.
12.2 Magnetic Field Due to a Thin Straight Wire
How would you orient two long, straight, current-carrying wires so that there is no net magnetic force between them? (Hint: What orientation would lead to one wire not experiencing a magnetic field from the other?)
12.3 Magnetic Force between Two Parallel Currents
Compare and contrast the electric field of an infinite line of charge and the magnetic field of an infinite line of current.
Is constant in magnitude for points that lie on a magnetic field line?
12.4 Magnetic Field of a Current Loop
Is the magnetic field of a current loop uniform?
What happens to the length of a suspended spring when a current passes through it?
Two concentric circular wires with different diameters carry currents in the same direction. Describe the force on the inner wire.
12.5 Ampère’s Law
Is Ampère’s law valid for all closed paths? Why isn’t it normally useful for calculating a magnetic field?
12.6 Solenoids and Toroids
Is the magnetic field inside a toroid completely uniform? Almost uniform?
Explain why inside a long, hollow copper pipe that is carrying an electric current parallel to the axis. Is outside the pipe?