Warmup
How are a voltage source and a capacitor different?
How are a resistor and an open switch similar?
Warmup
Start work on your circuits practice packet. Have out your Waves Lab writeup for
collection if not already turned in, plus Ch. 34 notes.
Warmup - Circuit Diagram Symbols
Voltage Source
Wire
Meter
Resistor
Capacitor
Inductor
Switch (closed)
Switch (open)
Ground
Warmup
1) What is different about an electric circuit system and an electrostatic system?
2) How does a transformer work?
Warmup
Which circuit elements can store energy in some form or another?
Which circuit elements rely on resistance in order to function?
What decimal value does the binary number 01100110 have?
Vocabulary
Concept
Variable
Unit Label
Definition
Voltage
V
Volts (V)
How hard the electrical field is
pushing electrons
Current
I
Amps (A)
(coloumbs/s)
How many electrons flow per
second
Resistance
R
Ohms (Ω)
How easily the material allows
the electrons to move
Power
P
Watts (W)
(coloumbs * volts/ s)
Work done per second
Charge
q
Coloumbs (C)
6.24×1018 electrons or protons
Inductance
L
Henries (H)
How much a current affects (and
stores potential energy) in
magnetic fields
Capacitance
C
Farads (F)
(coloumbs/volt)
How much charge can be built
up as a result of a voltage
April 11, 2012
Circuits Practice
Circuits Practice 1
Design a circuit that could produce a magnetic field of two different strengths.
Circuits Practice 2
Design a circuit that could take a 9V battery and produce a 4.5V source for something.
Circuits Practice 3
Design a circuit which uses two 2 Ω and one 5 Ω resistors to create a total of a 6 Ω
resistance.
Circuits Practice 4
Design a circuit which powers a 50W item, using 120V of potential, where the item
has a resistance of 1.5 Ω.
Circuits Practice 5
Design a circuit which sends 2A of current through one wire, and 1A of current through
the other wire.
Circuit Practice 6
Create a circuit diagram which charges a capacitor at 6V, using a 9V source, where
the capacitor can create a burst of magnetic fields in either direction.
Circuit Practice 7
Create a circuit which has a total resistance of 16,666 Ω using only 10,000 Ω resistors.
Circuit Practice 8
Create a circuit which flips a magnetic field back and forth, which is called an
electric motor.
Circuit Practice 9
A circuit has two 4 Ω resistors in parallel, which are in series with a 2 Ω resistor.
Draw the circuit and calculate the total resistance.
Circuit Practice 10
Two 5 Ω resistors are in parallel. This is combined in series with a 6 Ω
resistor and in series with three 6 Ω resistors in parallel. Draw the
circuit. Calculate the combined resistance.
Transistors
Transistor Construction
Resistors Color Code
Color
Sig.
figures
Multiplier
Tolerance
Black
0
×100
–
Brown
1
×101
±1%
Red
2
×102
±2%
Orange
3
×103
Yellow
4
×104
(±5%)
Green
5
×105
Blue
6
Violet
Temp. Coefficient
(ppm/K)
250
U
F
100
S
G
50
R
15
P
–
25
Q
±0.5%
D
20
Z
×106
±0.25%
C
10
Z
7
×107
±0.1%
B
5
M
Gray
8
×108
±0.05%
(±10%)
A
1
K
White
Gold
9
–
×109
×10-1
±5%
J
–
–
Silver
–
×10-2
±10%
K
–
None
–
–
±20%
M
–
–
–
To-do
Hands-on practice:
1) Resistors in series
2) Resistors in parallel
3) Current through a circuit with a known resistance
4) Voltage sources in series
Lab design:
1) Choose circuit or electrostatic-based system
2) Identify circuit elements needed to move object, or method
to generate charge.
3) Find resistances, calculate current, and see if voltage source
can provide it.
4) Troubleshoot anticipated problems with additional circuit
elements.