ELECTROMAGNETISM

Α magnetic field is created around a straight conductor when:

• The conductor is connected to a magnet.

• The conductor is leaked by current.

• The conductor is connected to a light bulb.

A magnet approaches a coil and enters in it.

• Inductive voltage is generated in the coil, only if the two ends of the coil wire are connected to each other.

• Inductive voltage is generated when there is movement of the magnet relative to the coil or movement of the coil relative to the magnet.

• Inductive voltage is created only if the coil is connected to a battery

The Laplace force applied to a straight current conductor located in a homogeneous magnetic field

• has the direction of dynamic lines.

• It depends on the intensity of the current flowing through the conductor.

• It is maximum when the conductor is parallel to the dynamic lines.

They receive magnetic forces when they are in a magnetic field

• all materials

• Only certain materials

• only ferromagnetic materials

The direction of Laplace force depends on:

• the direction of the electric current

• the direction of the magnetic field

• from all of the above.

When a coil is leaked by current, electric energy is converted into:

• heat

• magnetic field energy

• mechanic energy

• dynamic energy

The electric motor converts:

• the electric energy to mechanic energy

• the mechanic energy to electric

• none of the above

Electric generators convert:

• kinetic to electric energy

• electric energy to kinetic energy

• none of the above

Which of the following statements is NOT correct. The magnetic forces:

• penetrate the matter,

• are only attractive.

• They are forces that act from a distance.

• They are described in the sense of magnetic field.

You have an electromagnet, which is connected to the poles of a battery. When you approach small metal objects he attracts them. If you disconnect the battery then:

• The electromagnet continues to attract metal objects.

• The electromagnet no longer attracts metal objects.