# Electricity and Magnetism Review

Electronics - Devices

Oct 18, 2013 (4 years and 6 months ago)

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Electricity and Magnetism Review

Name: ________________________________ Date: __________________ Period: ___

1.
The common subatomic particle with a negative charge is the ____________________.

2
. The common subatomic particle with a positive charge is the

____________________.

3
. Electrical charges are usually due to objects having an gained or lost __________________.

4
. _____________________ is usually caused when dissimilar materials are rubbed together,

transferring electrons from one to the other. Thi
s transfer of electrons results in the objects

developing an electric charge.

5
. Electric charges on objects are either positive or negative. Objects with excess electrons have

_______________ charges whereas objects which have lost electrons have ________
_______

charges.

6
. Objects with electric charges exert forces on other charged objects. Objects with the same electric

charges (attract / repel) each other.

7
. Objects

with different (opposite) electric charges (attract / repel) each other.

8
. Electric ch
arges are measured in ____________________.

9
. ___________________ is the flow of electric charge. Usually we are referring to the movement

of electrons.

1
0
. Electrical current is measured in __________________ commonly abbreviated __________which

have the

symbol _____.

1
1
. Substances

which allow

the (easy) movement of electrons are called ____________________.

1
2
. Substances

which prevent the flow of electrical current are called ____________________. There

are no materials which perfectly prevent the flow

of electrical current.

13
.Virtually all substances ____________________ the flow of electrical current to some degree.

1
4
. Electrical ___________________ is the tendency of a substance to resist the flow of electrons (or

electric current).

1
5
. Electrical
resistance is measured in ________________ which have the symbol _____.

16
. ___________________ is the "push" behind electric current.

17
.One ____________________ is defined as the ability to do __________________ of work on

____________________ of electri
c charge.

18
. Electrical potential is measured in __________________ which have the symbol _____.

19
.Ohm's Law is a mathematical equation which relates ____________________,

____________________, and ______________________.

2
0
.Ohm's Law can be written:

21.
The variable represents and is measured in:

V

I

R

Solve these problems using Ohm's Law

2
2
.

If a 6 V battery is connected to a light bulb whose resistance is 55,000 Ω how much current will

flow in the circuit?

2
3
.A certain electric heater is rated for 120 V and a current of 10 A. What must be the minimum

resistance of the heating element?

2
4
. If I wanted to make a 10A current flow through a 250 Ω resistor what voltage should I apply?

25.A(n) ____________________ is a path for electricity to flow through.

26.A circuit is said to be ____________________ if electricity can flow through it a
nd

____________________ if electricity can not flow.

27. Please provide and the name of the electrical component represented by these symbols:

For the following questions consider circuits A, B, and C:

28. The circuit labeled
A
is (open / closed), t
his means that electrical current (can / can not) travel

around the circuit.

29. ____________________ circuits which allow only one path for electricity to follow.

30. ____________________ circuits which allow multiple paths for electricity to follow.

31.C
onsider circuit
B
, are the two light bulbs arranged in series or in parallel? _________________

32. If one of the light bulbs in circuit
A
is removed, the other light bulb (will / will not) continue to

glow.

33
. By

comparison to circuit
B
, the light bulbs

in circuit
C
are arranged in _____________________.

34. This means that if one of the light bulbs in circuit
C
is removed the other light bulb (will / will not)

continue to glow.

For the following questions consider circuits D and E:

35. In which circu
it are the batteries arranged in series? ______

36. In which circuit are the batteries arranged in parallel? ______

37. In which circuit will the light bulb glow most brightly? ______

38
. Which

flow?

___________________.

39
. Which

of the circuits on this page allow only one path for electricity to flow?

___________________.

40
. A

____________________ is a material or object that produces a magnetic field.

41
. A

magnetic field exerts a force on __
_________________ or ____________________.

42
. Magnetic

fields are always ____________________. Which means that they have two opposite

poles.

43
. A

common way to detect magnetic fields is with a magnetic compass. A magnetic compass

consists of a _________
___________ which is free to pivot (spin) and tends to line up with

magnetic fields.

44
. Magnetic

poles are usually labeled ____________________ and ____________________. The

end of a compass needle that points north is the "north" magnetic pole of the nee
dle. Laboratory

magnets are labeled the same way. The north end of a magnet is attracted (weakly) to a spot

near the geographic north pole of the earth.

45
. Since

magnetic dipoles line up "head to tail" (to minimize their magnetic potential energy) the

nor
th pole of one magnet is attracted to the ____________________ pole of another magnet.

46. The end of a compass needle that points to the magnetic pole located at the Earth's geographic

north (where Santa Claus and Eskimos live, but not penguins) actually
points to the

____________________ pole on a laboratory bar magnet like we use in class.

47
. Breaking

a magnet in half (does / does not) separate the poles and produces ________________

______________________________________________________________________
________.

48
. A

____________________ magnet is one that stays magnetized.

49
. A

____________________ magnet is one that loses its memory of previous magnetizations.

50
. An

____________________ behaves like a magnet when an electric current flows through it.

The simplest ____________________ is a single current carrying wire.

51. The strength of electromagnets can be increased (hundreds or thousands of times) by wrapping

the

wire around ____________________ (sometimes called “soft” magnetic materials).

52. The electromagnet can be made stronger by increasing either the _______________ flowing

through the wire or by increasing the _________________________ of the wire.