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

The<br/>magnetic field lines are used to visually describe the distribution<br/>of the magnetic field around the magnet. For the following<br/>statement,( <br/>) is wrong. A: Each<br/>magnetic field line is a closed loop curve B: No<br/>two magnetic field lines can cross each other C: The<br/>length of the magnetic field line reflects the strength of the<br/>magnetic field D: The<br/>tangential direction of any point on any of the magnetic lines is the<br/>direction of the magnetic field at that point

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.

Regarding the magnetism of the complex, the following statement is<br/>incorrect: ( ). A: The magnetism of complexes is one of the important properties of<br/>complexes B: If all substances are placed separately in a magnetic field, they can<br/>be divided into two groups according to their influence by the<br/>magnetic field: diamagnetic, paramagnetic, and ferromagnetic C: Ferromagnetism is a substance, which is strongly attracted by a<br/>magnetic field D: Most of substances are paramagnetic

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