28. Magnetic Fields and Forces

Which of the following materials is attracted to a magnet?

When two magnets are placed close together, which of the following best describes their interaction?

At point C near a straight current-carrying wire, what is the direction of the magnetic field $B$ produced by the current according to the right-hand rule?

When two bar magnets are placed with like poles facing each other so that they repel, what is the general pattern of the magnetic field lines between the magnets?

Which of the following statements is true about a $B$ field?

Which of the following statements about the creation of magnetic fields is correct?

In a diagram showing a bar magnet with magnetic field lines, which of the dashed boxes $a$–$d$ represents the position of the north magnetic pole?

When a positively charged particle moves through a uniform magnetic field, what determines the direction of its motion due to the magnetic force ($F$)?

At point D near a straight current-carrying wire, what is the direction of the magnetic field $B$ at point D?

Which of the following factors can affect the strength of a magnetic field produced by a current-carrying wire?

Which of the following best describes a magnetic field?

A current-carrying circular coil lies flat in the $xy$-plane with current flowing counterclockwise when viewed from above. In which direction does the magnetic field at the center of the coil point?

When a magnet spins near a conducting wire, does the changing magnetic field create an electric field that causes electrons to move in the wire?

Two long, straight, parallel wires carry currents in the same direction. What is the direction of the magnetic field produced by wire $2$ at the location of wire $1$?

A long straight current-carrying wire runs vertically upward. At point $z$, which is located to the east of the wire, what is the direction of the magnetic field produced by the wire at that point?