Download Electric Charge

Electricity Study Guide: Test on ________________
Electricity – the effect of the apparent motion by an electric current
Electric Current – the flow of charge
Electric Force – the push or pull of the electric charge
I. Two Kinds of Electric Charges:
a. Electric Charge – the basic property of the tiny particles (atoms) that make up
matter
1. Positive Charge, proton, +
2. Negative Charge, electron, 3. Neutron (Neutral)
b. Static Electricity – the buildup of charges in one place (clothes out of a
dryer...lightning strikes)
- Positive and Negative charges ATTRACT
(pull towards) each other
-Positive and Positive charges REPEL and
Negative and Negative charges REPEL (away)
II. Separating Charges
a. If two objects have the same amount of charges
(same + and same -) then nothing happens electrically
**this means both objects are neutral or have a neutral charge
b. If an object has more
If an object has more
(protons), then it has a positive charge.
(electrons), then it has a negative charge.
c. We can separate charges by rubbing objects.
d. Only negative charges can jump to another surface.
III. Electric Forces (You can use 2 balloons hanging from a string to
illustrate this)
*If there are two different forces
and
then the field attracts
towards each other and gets stronger
* If there are two of the same forces + and + or - and - , their
electric fields move away from each other and get weaker (repel)
IV. Circuits
a. Electric current- the path or flow of electric charges travels on
b. Electric circuit- is a closed path that electric current flows
c. Series circuit- has only one path for its current to follow
 In a series circuit, the more bulbs there are, the dimmer they are
because they are sharing the same electric current. If one light goes out
they ALL go out.
 A flashlight or a simple lamp use series circuits.
d. Parallel circuit- has more than one path for the current to
flow/follow
 In a parallel circuit, adding more bulbs does not make them dimmer
because they do not share the same electric flow of charges like a
series circuit does. If one light goes out the others do not.
 We use parallel circuits in our homes and businesses.
V. Conductors
a. are a type of material through which negative
(electricity can move through conductors easily)
b. copper and silver are great conductors
charges can move easily
VI. Insulators
a. material that resists (opposes) the flow of electricity
b. plastic and rubber make good insulators
Objects that Conduct
Electricity
Objects that Do Not
Conduct Electricity
silver spoon
plastic fork
iron nail
wooden handle
copper pan
glass block
gold ring
eraser
VII. Magnets and Electromagnets
a. Magnets create a force that pushes or pulls
 Magnets attract objects most strongly at their
poles.
 Like poles repel while unlike poles attract.
 The push and pull of a magnet is called the
magnet force.
 The magnetic field is where the magnetic
force is acting.
 Permanent magnets are usually made of steel.
 All magnets have a north pole and a south pole.
b. Electromagnet – a temporary magnet made by wrapping a coil carrying a
current around an iron core.
 Created by wrapping a wire around an iron core (nail) and
connecting both ends of the wire to a battery
 The electric current flows through the coiled wire and charges the
nail
 The nail is then magnetized and will remain an strong magnetic
force as long as the electric current flows
 When the power source is turned off, the magnetic field no longer
exists
 You can make it stronger by:
1. Wrapping more coils around the nail
2. Using a stronger battery
*Electricity and magnetism are closely related.
Electricity creates magnetism and magnetism creates
electricity because an electric current can make a magnetic
field and a moving magnet can make an electric current.
Prepare for Constructed Response
In class, we created an electromagnet using a nail, wire, and a battery. The diagram below
shows an electromagnet. First, explain how the nail is able to attract the paper clip. Second,
describe how the setup could be altered in order to lift a heaver metal object or more paper
clips. Your answers must be thorough to get full credit!
Practice Response Here…..
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