Download 01-02OhmsLaw-Template

Here are some graphics for the ohm’s law lesson.
Read through the book, work out the assigned problems,
and come up with a lesson plan (written on paper) for this
unit.
I have a box of resistors that you could pass around, and a
setup where you can change resistance and voltage and
watch a light bulb get dimmer or brighter.
I will have already taught them about current (I = q/t)
Symbols
+
-
A Cell. + and -, Infinite current, R = 0, what’s really
inside
A Battery of cells
A resistor
V3
A voltmeter, R = infinity
A3
An ammeter, R = 0
Ohm’s Law
V = Voltage (like pressure)
I = Current (like flow rate)
+
-
V
A = ammeter
– measures
current
A
R
R=V
I
R = Resistance in ohms ()
V = Voltage in Volts (V) (pressure)
I = Current in Amps (A) (flowrate)
Ohm’s Law – re written for current
V = Voltage (like pressure)
I = Current (like flow rate)
R = Resistance to flow
+
- V
I=V
R
R = Resistance in ohms ()
V = Voltage in Volts (V) (pressure)
I = Current in Amps (A) (flowrate)
A
R
Ohm’s Law
I=V
R
+
-
R = Resistance in ohms ()
V = Voltage in Volts (V) (pressure)
I = Current in Amps (A) (flowrate)
They don’t need to know the color code
Demo - pass around resistors
(two properties - power and resistance)
Demo - power supply, resistor, light bulb
(show increase/decrease V, and R)
A
V
R
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
Gold
Silver
No color
0
1
2
3
4
5
6
7
8
9
5%
10%
20%
Ohm’s Law
+
-
12.0 V
R=V
I
R = Resistance in ohms ()
V = Voltage in Volts (V) (pressure)
I = Current in Amps (A) (flowrate)
Example 1:
A
120. mA
R= ??
Ohm’s Law
+
-
12.0 V
R=V
I
R = Resistance in ohms ()
V = Voltage in Volts (V) (pressure)
I = Current in Amps (A) (flowrate)
Example 1:
A
120. mA
R= ??
Whiteboards – you need
about 6 because they are
so simple
1|2|3|4|5|6
A light bulb has a resistance of 1200. Ω, and is
hooked up to 240. volts. What current flows
through it?
Given:
R=V
I
R = 1200 Ω
V = 240 V
I=?
I = V/R = 240/1200 = 0.20 A = 200. mA
0.200 A of 200. mA
question goes here
Given:
R=V
I
R=
V=
I=
Put your solution here
answer goes here
question goes here
Given:
R=V
I
R=
V=
I=
Put your solution here
answer goes here
question goes here
Given:
R=V
I
R=
V=
I=
Put your solution here
answer goes here
question goes here
Given:
R=V
I
R=
V=
I=
Put your solution here
answer goes here
question goes here
Given:
R=V
I
R=
V=
I=
Put your solution here
answer goes here