举一反三
- ______every magnet is surrounded by a magnetic field. A: It is believed that B: It believes that C: It believed that D: It's believing that
- _____ magnet in a magnetic field will be subject to _____ force. A: A; a B: The; the C: A; the D: the; /
- An inductor stores energy in a magnetic field _________ an electric field.
- The region around a magnet where magnetic forces act is sometimes called a electric field.
- <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>
内容
- 0
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
- 1
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.
- 2
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
- 3
There is no magnetic field in an ideal conductor, but there is a magnetic field inside because of the surface current。
- 4
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