Electromagnetism Pretest

What do you call the ends of a magnet?

• Magnetic Poles

• B. Magnetic Compass

• Magnetic Field

• Magnetic Domain

Which of the following best describe for the poles magnets that attract each other?

• both poles are of the same kind

• both poles must be N poles

• both poles must be S poles

• one pole is an S and the other is an N

Which of the following process occur when magnetizing a piece of iron?

• each atom in the iron is converted into a magnet

• existing atomic magnets are brought into line

• magnetic atoms are added to the iron

• magnetic lines of force are brought into line

Which of the following explains the rotation of needle when a compass is placed in a magnetic field?

• because the field attracts N poles

• because the field is produced by a magnet

• because the field comes from the center of the Earth

• because the field exerts forces on the atomic currents in the compass needle

Which of the following justifies why a magnet will attract a wire?

• The wire exerts an electric force.

• The wire has a small mass.

• The wire has current flowing through it.

• The wire is long.

Which of the following explains why the iron atom acts as a magnet?

• The iron has an equal number of protons and electrons.

• The electrons have a spinning motion.

• The electrons have negative charge

• The neutrons have no charge

Which of the following act will make an iron needle into a magnet?

• Bang it on a table

• Soak it in mercury

• Place it near a compass

• Stroke it with a magnet in one direction only

Which of the following will make an electromagnet stronger?

• increase the current in the coil

• add an iron center in the coil

• increase the number of loops in the wire

• all of the above

Which of the following will happen if two unlike poles placed near each other?

• The lines of force will curve away from each other

• The lines of force will connect the poles

• The lines of force will cancel each other

• Nothing will happen.

Which of the following scientist discovered that an electric current affects the action of a magnetic needle?

• Ampere

• Oersted

• Faraday

• Franklin