<p><p>1. A charged particle is traveling through a uniform magnetic field. Which of the following statements are true of the magnetic field? </p></p>

A small piece of ferromagnetic media (the relative permeability is much greater than 1) is placed in a vacuum uniform magnetic field. Compared with the surrounding magnetic field, the magnetic strength in the media will ________, the magnetic field strength will __________. A: increase; increase B: increase; decrease C: decrease; decrease D: decrease; increase

Which of the following explains why a magnetic field does no work on a moving charged particle?( ) A: The magnetic force depends on the speed of the particle. B: There is always an electric field that cancels the work done by the magnetic field. C: The magnetic force is always perpendicular to the direction of motion. D: The magnetic force depends on the direction of motion of the particle. E: The magnetic force is conservative.

The curl equation [img=154x44]1803a2a153c85f5.png[/img]shows that : A: The time-varying magnetic field can generate an electric field, in which the elecric field lines is closed around the magnetic field line. B: The time-varying magnetic field can generate a magneitc field, in which the magnetic field lines is closed around the electric field line. C: The magnetic field lines is closed themselves. D: Flux continuity

There is no magnetic field in an ideal conductor, but there is a magnetic field inside because of the surface current。