Physics
Littlewood
Name: __________________
Period: ___ Date: _________
Chapter 35 Notes
Electric Circuits
Key Terms:
circuit
series circuit
parallel circuit
schematic diagram
in series
in parallel
Objectives:
Circuits
1.define "electric circuit" (35.1)
2.distinguish between a series, parallel, and compound circuits.(35.2)
Series Circuits:
3.state that a series circuit provides a single conducting path for charges.(35.1)
4.state what happens to other devices in a series circuit when one device fails.(35.3)
5.state that the current must be the same in all parts of a series circuit. (35.3)
6.state that the total voltage in a series circuit is the sum of the voltages across the separate
components. (35.3)
7.calculate the equivalent (total) resistance in a series circuit as the sum of the individual
resistances. (35.3)
8.apply Ohm's Law to a series circuit. (35.3)
Parallel Circuits:
9.state that the voltage is the same across each device in a parallel circuit. (35.4)
10.state what happens to other devices in a parallel circuit when one device fails.(35.4)
11.apply Ohm's Law separately to each branch of a parallel circuit.(35.4)
12.calculate the total current as the sum of the branch currents. (35.4)
Resistance
13.state that the equivalent (total) resistance of a parallel circuit decreases as the number of
branches increases.(35.7)
14.calculate the equivalent (total) resistance of two equal resistances connected in parallel. (35.6)
15.estimate the equivalent (total) resistance of two unequal resistances connected in parallel.(35.6)
Overloading
16.state that electrical devices in our homes are connected in parallel. (35.7)
17.state that the total current in a parallel circuit increases as each additional device is added to the
circuit. (35.7)
18.state that the total energy supplied to a parallel circuit increases as each additional device is added
to the circuit. (35.7)
19.tell what a short circuit is, and why it is dangerous. (35.7)
20.discuss the use and operation of fuses and circuit breakers. (35.7)
Compound Circuits
21.calculate the equivalent (total) resistance of resistors in a compound circuit. (35.6)
22.apply Ohm's Law to find the total current in a compound circuit. (35.6)
23.apply Ohm's Law to each individual component of a compound circuit. (35.6)
Chapter 34: Electric Circuits
A. CircuitB. Schematic diagrams-a diagram that describes an electric circuit, using special symbols to represent
different devices in the circuit.
Battery
light bulb
electric wires
Example of a circuit with one battery and one resistor.
B. The direction of current-
D. There are two types of circuits.
1.
2.
E. Series circuit-
1.
Single pathway
2.
Disadvantages -
3.
Equivalent (total) resistance is the
Req =
4.
Total voltage equals
V =
5.
Current =
I=
Ohm's Law applies to each separate device
resistor
capacitor
Example: Three resistors 4O, 8O and 12 O are connected in series to a 12 volt battery. Calculate the
equivalent resistance, the current through the circuit and the voltage across the individual resistors.
F. Parallel Circuit –
1.
Equivalent resistance
2.
Voltage
3.
Ohm's Law applies separately to each branch
4.
Total current
5.
As the number of branches increases the equivalent (total) resistance __________
Equivalent (total) resistance of 2 equal resistances is ___________ the individual
resistance.
Equivalent (total) resistance of 2 parallel branches is _________ than the smallest
resistance
Example: Three resistors 3O, 6O and 12O are connected in parallel. Calculate the equivalent resistance,
and the current through each resistor.
G.
Overloading
1. Home circuits connected ____________________.
2. As each device is added, total current __________________, and the total energy supplied
is __________________.
3. fuse and circuit breakersFuses burn out, whereas circuit breakers can be reset.
4. short circuit-
H.
Compound Circuits - examples