A: operation of electrical equipment and generators on board ship
B: the earth's magnetic field affecting the ship's hard iron during construction
C: the horizontal component of the earth's magnetic field acting on the horizontal soft iron
D: the vertical component of the earth's magnetic field acting on the vertical soft iro
举一反三
- 14. The magnetic compass magnets are acted on by the horizontal component of the Earth's total magnetic force. This magnetic force is GREATEST at the ______.
- With the help of suspended magnetic element, a compass can aid people by ______ of the horizontal component of Earth's magnetic field.
- When the external magnetic field is removed, most or all of the magnetism of soft magnetic materials will not be lost, and the coercivity is very large.
- If magnetic compass is not affected by any magnetic field other than the Earth’s, which statement is TRUE ___. A: Compass error and variation are equal B: Compass north will be true north C: Variation will equal deviation D: There will be no compass erro
- Which of the following is NOT an example of accelerated motion? A: Vertical component of projectile motion B: Circular motion at constant speed C: A swinging pendulum D: Earth’s motion about sun E: Horizontal component of projectile motion
内容
- 0
It follows from Maxwell’s hypothesis(假设) that whenever there is a change in an electric field, a magnetic field is produced.
- 1
It will not be necessary to calculate the component of the velocity perpendicular to (垂直于) the magnetic field(磁场).
- 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
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
- 4
There is no magnetic field in an ideal conductor, but there is a magnetic field inside because of the surface current。