Download Ch 7: Static Charge and Electron Transfer Ch 8: Ohm`s Law

Ch 7: Static Charge and Electron
Transfer
Ch 8: Ohm’s Law- Current, Voltage,
and Resistance
Ch 9: Series/Parallel Circuits; Power
Name_________________
Section 7.1:
Static Charge
Pages__________
By the end of section 7.1 you should be able to understand the following:
� Static charge is electric charge that is held in one place
� An atom or material becomes charged when electrons transfer into it or out of it
� Insulators keep charges in one place, whereas conductors allow charges to move
more easily
Words to Know
Definition
acetate
conductors
coulomb
electrons
grounding
insulators
static charge
Van de Graaff
generator
Questions- Cornell Notes
1. Describe
Benjamin
Franklin's early
theory of
electricity.
2. In what way
was this theory
wrong?
3.How can an
atom become:
a)positively
charged?
b) negatively
charged?
a)
b)
4.What role does
friction play in
electron transfer?
5. How do insulators
and conductors
compare?
6. Name the unit
that charge is
measured in. What
number does it
represent?
7.How does a Van de
Graaff generator
generate charge?
7.Name four uses
of static electricity.
Be varied in your
answers.
8. What are two
dangers of static
electricity, and how
can each be
avoided?
Section 7.2:
Electric Force
Pages_________
By the end of section 7.2 you should be able to understand the following:
� Static charge is electric charge that is held in one place
� Like charges repel. Opposite charges attract. Neutral objects are attracted to
charged objects.
� Electric force is a force at a distance.
� Electric force can be increased by increasing the amount of charge on objects and
by decreasing the distance between charged objects.
Words to Know
Definition
action-at-a-distance forces
charging by conduction
charging by induction
contact forces
electric force
force
laws of static charge
Cornell Notes
1.
1.What are the laws
of static charge?
2.
3.
2. How is charging
by induction and
conduction
different? Draw and
label an example of
each.
3. Why do neutral
objects attract to
charged objects?
4. Draw the steps
which show a
balloon getting
charged and stuck
to a wall that is
neutrally charged.
Section 8.1: Electric Potential Energy and Voltage
Pages____
By the end of section 8.1 you should be able to understand the following:
 Static charge is electric charge that is held in one place
 Unlike charges gain electric potential energy when they are moved farther
apart.
 Voltage (potential difference) is the change in potential energy per coulomb
of charge.
 Electrical energy depends on the amount of charge and the voltage.
electrochemical cells
electrodes
electrolyte
energy
volt
voltage
1.What is another
term for electric
potential energy?
2.How is voltage
produced?
4. Draw and label the
parts of a dry cell and
a wet cell.
5. Name 5 sources of
electrical energy that
we use today.
1.
2.
3.
4.
5.
Section 8.2:
Electric Current
Pages_________
By the end of section 8.2 you should be able to understand the following:
� Current electricity is the continuous flow of charge in a complete circuit.
amperes
circuit diagrams
current electricity
electric circuit
electric current
electric load
1. Describe how energy
flows in a circuit.
(see p. 281)
1.
4.
2.
5.
3.
2. Draw and name
the symbols for
the components
in a circuit. Include
a resistor.
3. How does current
electricity differ from
static electricity?
4. What is the unit for
electrical current? What
device is used to
measure current?
5. What is conventional
current? How is it used
today?
1.
5.
2.
6.
3.
7.
4.
8.
In the eight diagrams below, the electric light will not work.
(a) Use the spaces provided to explain what is wrong with each arrangement.
(b) Then explain what needs to be done in this case to create a working circuit.
3.
1. a)The wire does not
touch the side of the bulb.
b) Move the upper end of
the wire to the metal side
of the bulb.
2.
4.
5.
6.
7.
8.
Section 8.3: Resistance and Ohm's Law
Pages____
By the end of section 8.3 you should be able to understand the following:
� Ohm’s law states that the electrical resistance of the circuit is the ratio of the
voltage to the current.
electrical resistance
ohm
Ohm's law
resistance
resistor
1. How is resistance
related to current?
2. What is Ohm's Law
and how is it used in
resistance calculations?
Give the equation.
3. By what two methods
is resistance determined?
4. What is a resistor and
how does the resistor
colour code work?
Section 9.1:
Series and Parallel Circuits
Pages_____
By the end of section 9.1 you should be able to understand the following:
 The current is the same in each part of a series circuit, and each load uses a
portion of the same voltage.
 The current in each part of a parallel circuit depends on the resistance of that path.
 When resistors are placed in series, the total resistance of the circuit increases.
 When resistors are placed in parallel, the total resistance decreases.
junction point
parallel circuit
series circuit
Draw a circuit with
1.
a) open switch
b) two cells in series
c) two bulbs in series
d) 1 voltmeter around
both bulbs
2.
a) closed switch
b) two cells in parallel
c) two bulbs in series
d) 2 voltmeters, one
around each bulb
3.
a) open switch
b) two cells in parallel
c) two bulbs in
parallel
4.
a) closed switch
b) three cells in series
c) two resistors in
parallel
1. How is voltage and
current distributed
among the loads in a
series circuit?
Voltage:
Current:
2. What happens to
the total resistance in
a series circuit when
resistors are added?
3. How is voltage and
current distributed
among the loads in a
parallel circuit?
Voltage:
Current:
4. What happens to
the total resistance in
a parallel circuit when
resistors are added?
IN SUMMARY…
What happens to…
…in a Series Circuit?
…in a Parallel Circuit?
…the flow of
electrons if the
circuit is broken
…the current along
the circuit?
…the voltage lost
across each resistor?
…the total resistance
if resistors are added
total resistance will
__________________
total resistance will
________________
…the current if
resistors are added?
current will
___________________
current will
________________
IN SUMMARY… (Answers)
What
happens to…
…the flow of
electrons if
the circuit is
broken?
…the current
along the
circuit?
…in a Series
Circuit?
…in a Parallel
Circuit?
the current
stops- all
electrons are
blocked
all electrons flow
along alternate
routes in the
circuit
the current is
equal
the current is
split among the
pathways (total
current = sum of
the paths)
total voltage =
…the voltage
sum of the lost
lost across
voltages in each
each resistor?
load
…the total
total resistance
resistance if
will increase
resistors are
added
…the current if
current will
resistors are
decrease
added?
the voltage
across each load
are equal
total resistance
will decrease
current will
increase
Section 9.2:
The Power of Electricity
Pages_____
By the end of section 9.2 you should be able to understand the following:
� Electric power is the rate at which electric potential energy
is transformed.
� Power consumption multiplied by time of use equals
the amount of electrical energy used by a device.
Term
Unit
joule
kilowatt•hour
power
power rating
watt
1. What is electrical
power and what unit is
used?
2. How is electrical
power calculated? Give
the equation.
3. a) How is a
kilowatt•hour used to
charge consumers for
electricity?
c) Give a mathematical
example.
4.a) What is an electric
surge?
b) How do you protect
yourself against one?
Definition and Equation