29. Sources of Magnetic Field

A positive point charge moves to the right along the $x$-axis. At point A, which is located above the $x$-axis (in the positive $y$-direction), what is the direction of the magnetic field $B$ produced by the moving charge at point A?

Which of the following best describes magnetic domains in the context of the $B$ field produced by moving charges?

Which of the following is primarily responsible for producing a magnetic field?

What are the invisible lines revealed by the iron filings surrounding a magnet called?

Which of the following is a property possessed by every magnet?

Which of the following factors primarily determines the strength of the magnetic field produced by a current-carrying straight conductor at a given point near the wire?

Based on the magnetic field line diagrams, which of the following correctly describes the direction of the magnetic field around a straight, long current-carrying wire?

Which of the following best describes the magnetic field lines around a single bar magnet?

Which of the following best describes the magnetosphere?

When you split a bar magnet in half, what happens to the magnetic poles of the resulting pieces?

In the context of the magnetic field produced by moving charges, how many magnetic poles does a typical magnet have?

In the context of magnetic fields produced by moving charges, what are the opposite ends of a magnet called?

If the $\mathrm{Earth}$ were completely solid and did not have a liquid outer core, how would this affect the generation and appearance of its magnetic field?

Which of the following best describes how electromagnets are similar to other magnets?