Permanent magnetism is caused by（）.
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
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