Download Magnetism and Electromagnetism Review Answers

Test Review
Magnetism &
Electromagnetism
1. What are the 3 metals that are
ferromagnetic?
iron, nickel, and cobalt
2. The reason a magnet can attract an unmagnetized nail is that nails become
( temporarily / permanently ) magnetized
in a magnetic field.
temporarily
3. How does an iron rod become
magnetic?
When the net spin of its electrons point
in the same direction.
4. Where is the magnetic field strength the
strongest in a magnet?
at the poles
5. Earth’s geographic North Pole of the
earth is close to its magnetic _______ pole.
South
6. Which pole of a compass needle points
to the south pole of a magnet?
North
7. What are magnetic domains?
Regions of atoms magnetically aligned.
8. If you break a bar magnet in half, what happens
to the 2 halves?
You get 2 bar magnets with 2 poles
9. How are magnetic field lines surrounding a
magnet conventionally drawn?
From south to north
OR
From north to south
From north to south
10. The picture below shows the magnetic field of 2
magnets, a ___ pole on the right and a ____ pole on
the left.
North; North
11. The picture below shows the magnetic field of 2
magnets, a ____ pole on the right and a ____ pole
on the left.
North; South
12. If the opposite poles of magnets are brought
near each other, what will happen?
They will attract
13. If 2 like poles of a magnet are brought
near each other, what will happen?
They will repel
14. If you put a compass in a magnetic field,
the compass will line up ( randomly / parallel
/ perpendicular ) to the magnetic field lines.
parallel
15 a. Where is the magnetic field the strongest?
At Point A
15 b. Where is the direction of the current in the
wire directed?
down
16. If you bent the wire into a loop, like the picture
to the right, where is the magnetic field the
strongest?
at the center
17. What do you need to make an
electromagnet?
battery, wire, and a nail
18. What is electromagnetic induction?
Inducing voltage by changing the magnet
field around a conductor.
19. The magnetic field strength of an
electromagnet will be greater if the wire’s
( resistance / temperature / current ) is
increased.
current
20. The magnetic field strength of an
electromagnet will be decreased if the number of
coils of a solenoid is ( increased / decreased / stays
the same ).
decreased
21. The magnetic field strength of an
electromagnet will be greater if the curled wire
encloses ( a wooden block / an iron rod ).
an iron rod
22. Using the 1st right hand rule, where does your
thumb point?
in the direction of the conventional current.
23. Electricity is transmitted from the power plant to
your home using ( AC / DC ) circuits.
AC
24. Label where the north pole would be in the
electromagnet illustrations?
N
N
25. Magnetic fields could be produced by particles
that are ___.
a. Moving and neutral
c. Stationary and charged
b. moving and charged
d. stationary and neutral
b. moving and charged
26. When a loop of wire is rotated, like in the
magnetic field shown, what is produced in the wire?
a current
27. A transformer works due to the mutual induction
created by a changing _________ __________.
magnetic field
28. A generator converts ( potential / kinetic )
energy into ( electrical / mechanical ) energy.
kinetic; electrical
29. What is the energy source of a generator?
turbine; also has a magnet & a coil of wire
30. A device that transforms electrical energy to
kinetic energy is a ( generator / transformer / motor).
motor
31. A device that uses 2 coils around an iron core to
change the voltage across a circuit is called a (
generator / transformer / motor ).
transformer
32. Transformers ( increase / decrease ) the current
in the transmission lines to reduce the risk of electric
shock in your home.
decrease
33. In the transmission of electricity, electricity is
transmitted at a ______ voltage and ______ current.
high; low
34. A step-down transformer ( increases / decreases)
voltage.
decreases
35. In a fossil fuel power plant, ( water / wind /
steam) turns the turbine.
steam