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?

Which part of the $Earth$ is primarily responsible for generating the planet's magnetic field?