Chapter 20.3
 Key
Concepts:
• What is included in a circuit diagram?
• How do series and parallel circuits differ?
• How do you calculate electric power and electrical energy used?
 Vocabulary:
• Electric circuit
• Series circuit
• Parallel circuit
• Electric power
Use
symbols to represent
parts of a circuit.
Include:
• Sources of electrical
energy
• Devices that are run by
electrical energy
Each battery = 1.5V
Charge
has only ONE path through
which it can flow.
If
one element stops functioning in
a series circuit, NONE of the
elements can operate.
• The bulbs in a circuit are a source of
resistance. The more bulbs, the more
resistance.
 Voltage
is split
equally among the
resistors in the
circuit.
+
6V
3V
-
 Current
is the same
throughout the
circuit.
0V
 What
would the voltage
be at each bulb if the
total voltage is 9 V.
 How
could you make
each bulb brighter
Charge
has TWO OR MORE paths
through which the charge can flow.
If
one element stops functioning, the
rest of the elements can still
operate.
Parallel
Series
Power
is the rate of doing
work.
• Power is measured in WATTS
(W).
Electrical
power is the rate at
which electrical energy is
converted to another form of
energy.
Electrical power is calculated by
multiplying voltage by current.
P (watts) = I (amps) x V (volts)
Electrical
power is calculated by
multiplying voltage by current.
Power (P) = Current (I) x Voltage (V)
(W)atts
(A)mps
(V)olts
 An
electrical oven is connected to a 240volt line, and it uses 34 amps of current.
What is the power used by the oven?
P = I xV
P = 34A x 240 V
P = 8200 W
Math Practice
• Page 611
Problems 1 – 3
• Page 613
Problem 7 - 8
How
much energy is used by
an appliance.
• Energy = Power x Time
•E=Pxt
• Unit = kilowatt-hours