Magnetic field

Magnets – questions.

1. What kind of magnetic poles do we know?

2. How do we recognize the north (North seeking) pole?

3. Which magnetic pole is situated in Antarctica?

4. How do the like and unlike poles behave?

5. What is the source of magnetic field ? How does it originate?

6. What is induced magnetism?

7. What are permanent and what are temporary magnets?

8. How to magnetize some materials?

9. What kinds of materials do we distingush by their magnetic properties?

10. What are ferromagnetic materials? What is the difference between soft and hard ferromagnetics?

11. How to demagnetize permanent magnets?

--------------------------------------------------

1. Describe three properties of the magnetic field induced by electric current in a streight wire conductor.

a. The shape of magnetic field lines

b. Magnetic field strenth and the distance from the wire.

c. . Magnetic field strenth and the current in the wire

2. Explain the Ampere right – hand grip rule for a streight wire.

3. Explain the Ampere right – hand grip rule for a coil.

4. Describe three properties of the magnetic field induced by electric current in a coil.

a. Compare magnetic field in a coil and a bar magnet.

b . Magnetic field strenth and the current in the wire

c. Magnetic field strenth and the number of turns in the coil.

5. What will happen if we put a ferromagnetic core into a coil with electric current?

Videá: