Download Chapter 11 - Electricity and Its Production Summary

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Mechanical energy, thermal energy and radiant energy are transformed into
in power plants
Electrical Power is
Power is expressed in the unit
(W).
Electrical energy is measured in
(kWh). Electrical energy if often measured in large
quantities, so we tend not to measure in Joules.
Electrical energy generated in Power Plants is usually measured in
(MWh)
𝑷=
∆𝑬
∆𝒕
HOMEWORK: Read Page 504-507 and Complete #2,3 on Page 507
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Electric Potential is the

. Electric potential energy is the energy
required to overcome the
Electrical Potential Difference, V is the
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When electrons leave a source, they have an increased electric
potential. This is a
.
When electrons leave any load, they have a decreased electric potential. This is a
Voltmeters are devices that are used to measure voltage (Circuit Symbol:
Voltmeters must be connected in
Potential
𝑽=
∆𝑬
𝑸
.
)
Difference
Change in
Potential Energy
Amount of Charge
V
Volts (V)
E
Joules (J)
Q
Coulombs (C)
I
Q
t
Amperes (A)
Coulombs (C)
seconds (s)
HOMEWORK: Read Page 510-513 and Complete #2,3,6 on Page 513
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Direct current (DC) - the flow
The reason electrons can move freely in a circuit is because the
outer electrons in the atom of a metal are not tightly held together
When current passes through your body, it can affect the current
that allows your nervous system to function
At 0.0008 A,
. At 0.051 A,
. At 0.50 A,
Ammeter are device used to measure current (Circuit Symbol:
Ammeters must be connected in
𝑰=
𝑸
∆𝒕
HOMEWORK: Read Page 516-518 and Complete #2,3 on Page 518
);
Electric Current
Amount of Charge
Time
ANALOGY FOR
POTENTIAL DIFFERENCE AND
CURRENT
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Kirchhoff’s Voltage Law (KVL) – In any complete path in an electric circuit, the total electric potential
increase at the source(s) is equal to the total electric potential decreases throughout the rest of the circuit.
𝑽𝒔𝒆𝒓𝒊𝒆𝒔 = 𝑽𝟏 + 𝑽𝟐 + 𝑽𝟑 + ⋯
𝑽𝒑𝒂𝒓𝒂𝒍𝒍𝒆𝒍 = 𝑽𝟏 = 𝑽𝟐 = 𝑽𝟑 = ⋯

Kirchhoff’s Current Law (KVL) – In a closed circuit, the amount of current entering a junction is equal to the
amount of current exiting a junction.
𝑰𝒔𝒆𝒓𝒊𝒆𝒔 = 𝑰𝟏 = 𝑰𝟐 = 𝑰𝟑 = ⋯
𝑰𝒑𝒂𝒓𝒂𝒍𝒍𝒆𝒍 = 𝑰𝟏 + 𝑰𝟐 + 𝑰𝟑 + ⋯
HOMEWORK: Read Page 519-522 and Complete #1,2 on Page 522
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Electrical Resistance,R is the
A resistor is an electrical device that has a specific resistance value. (Circuit Symbol:
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Ohm’s Law: The voltage in a conductor is proportional to the current (if temperature remains the same)
.
)
𝑽 = 𝑰𝑹
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Ohmmeter are devices used to measure electrical resistance. (Circuit Symbol:
Ohmmeters must be connected in
.
)
HOMEWORK: Read Pages 523-526 and Complete #1-6 on Page 526
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Equivalent resistance is the total resistance of a group of resistors in a circuit.
𝑹𝒔𝒆𝒓𝒊𝒆𝒔 = 𝑹𝟏 + 𝑹𝟐 + 𝑹𝟑 + ⋯
𝟏
𝑹𝒑𝒂𝒓𝒂𝒍𝒍𝒆𝒍
=
𝟏
𝟏
𝟏
+
+
+⋯
𝑹𝟏 𝑹𝟐 𝑹𝟑
HOMEWORK: Read Pages 527-530 and Complete #1,2,5 a-d on Page 530
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Circuits can be analyzed using a combination of the formulas for Kirchoff’s Laws, Ohm’s Laws and
Equivalent Resistance
HOMEWORK: Read Pages 531-535 and Complete #1b, 2-4 on Page 535
COMMON ELECTRICAL SYMBOLS:
Battery with
Battery with
one cell
two cells
Variable DC
Connecting
Power Supply
Wire
Battery with
three cells
Open Switch
Closed Switch
Resistor
Motor
Light
Bulb/Lamp
Fuse
Voltmeter
ELECTRICAL QUANTITIES SUMMARIZED:
Symbol Name
Units
Meter and its Circuit
(Symbol)
Diagram Symbol
In Series:
In Parallel:
V
Voltage
Volts (V)
Voltmeter
VT =
VT =
I
Current
Ampere (A)
Ammeter
IT =
IT =
R
Resistance
Ohms (Ω)
Resistance
RT =
RT =
Example Problems for 11.6, 11.8 and 11.9
Apply Kirchhoff’s Laws and Ohm’s Law and Equivalent Resistance to fill in the missing information in
the circuits.
I1 = 2 A
IT =
I1 = ____
____
V2 = ______
R2 = ____ V3 = ____
V4 = ____
I4 = 1.5 A
I1 = ____ I2 = 1 A
I3 = _____
V3 = _____
I1 =
IT = _____
VT = _____
RT = _____
R1 = _____
V1 = 9 V
V2 = _____
I2 = _____
I3 = _____
V3 = 7 V
3
= ______
R4 = ____