Download Electricity Hands-On #1

Electricity Hands-On #1 – Assembling Circuits
Create a Series
Circuit
Series Circuit
items
Draw circuit with symbols
Signature
of teacher
Brightness of
bulb #1 with
switch open
Brightness
of bulb #1
with
switch
closed
One light bulb,
one battery, one
switch
(Fig. 1)
Two light bulbs,
one battery, one
switch
Two light bulbs,
two batteries,
one switch
Explain what happens when
you move up and down the
resistor.
Two batteries,
one light, one
switch, variable
resistor
(Fig. 2)
Summary statement about series circuits: ______________________________________________
________________________________________________________________________________
Fig. 1
Fig. 2
Page 1
Where might variable
resistors be used?
___________________
Create a Parallel
Parallel
Circuit items
Circuit
Draw circuit with symbols
Signature of
teacher
Brightness of
bulb #1 with
switch closed
Brightness of
bulb #2 with
switch closed
Two light
bulbs, one
battery, one
switch
(Fig. 3)
Two light
bulbs, two
batteries, one
switch
Two light
bulbs, two
batteries, two
switches
Summary Statement about parallel circuits: _____________________________________________
________________________________________________________________________________
Reread p.610 to help you . . .
Compare and contrast series and parallel
Circuits:
Similarities:
Differences:
Advantages/Disadvantages:
Fig. 3
Page 2
Electricity Hands-On #2 – What is a Current?
Using a Galvanometer
Construct the circuit and then position the compass as shown in the
drawing.
Close the switch and observe the needle of the compass.
Open the switch and observe the needle.
Move the compass to different spots around and inside the coil. Each
time, observe which end of the needle points toward the coil when you
close and then open the switch. Record your observations.
Observations:
____________________________________________________________
Compass
________________________________________________________________________
________________________________________________________________________
Teacher Signature ___________________
Construct the galvanometer circuit as shown in the drawing below.
To help balance the pointer, stick the paper clip on top of the magnet.
Move the clip to the left or right a little at a time until the pointer
balances straight up and down on the 0 line.
Observe what happens as you close and open the switch. Record your
observations:
_______________________________________________________________________
Now look at the circuit diagram of the galvanometer circuit.
Identify the battery and the switch.
The remaining part of the circuit are represented by the G
symbol.
Draw the circuit diagram with the switch, battery, and galvanometer:
_____________________________________
Read the textbook pp. 636-638. In your own words, explain how a galvanometer works and give 2
practical uses:
Explain what the Galvanometer measures:
* Stop here until the demonstration **
Page 3
Do not continue until you have seen the demonstration
Electricity Hands-On #3 – Voltage and Amperage
Using a Digital Multimeter (DMM)
Measuring Volts (force):
Batteries store energy. This energy is rated in Volts. 1 volt = 1 Joule per Coulomb of charge in the
battery. If a battery has a charge of 6 volts, each Coulomb of charge has 6 Joules of energy. Using
your textbook p. 414, a Joule is a unit of ___________ which is __________x__________.
How many volts are in your battery? ________
So, how many Joules of energy does each Coulomb of electrons produce? _________
Voltage must be measured around a load. This means the circuit will be built, and then the
multimeter will be place with one wire on one side of the load, and the other wire on the other side
of the load. The circuit does NOT have to be taken apart to measure the force.
Draw and build a series circuit with 1 battery, 1 switch, 1 light, and 1 voltmeter measuring the
voltage of the light bulb.
Drawing of circuit
Teacher signature.
V = __________
Measuring Amps (speed of current or flow of electric charge):
Energy must travel out of the battery, through the load, and back to the battery. The speed at which
this happens is the Current, measured in Amps.
1 Amp = 1 Coulomb/second
Reread pp.600-601 and fill in the blanks: A coulomb = _____________ electrons. Lightning
produces ______________ coulombs. A flash camera uses about ________________ coulombs for
a flash.
Amperage must be measured with an ammeter in series, just behind a load. Therefore the circuit
must be broken and the DMM placed into the circuit to read amps.
Draw and build a series circuit with 1 battery, 1 switch, 1 light, and an Ammeter, measuring the
current just behind the light bulb.
Drawing of circuit
Teacher signature.
Amps = _________
Using Ohm’s Law (see p. 607), determine if your measurements on this page work. Show math:
Page 4
Electricity Hands-On #4 – Voltage and Amperage
Series
To measure the voltage (V) the meter must be placed around the load.
Measuring amps (I) must be done in series behind a load.
Use this diagram for
each test
Load being tested
Voltage
Teacher
Signature
VB
VB
V1
V1
V2
V3
V2
V3
+ V2 + V3 = _____________ volts
Is this answer close to VB ? _______
V1
IB
I2
Current being tested
Amps
Teacher
Signature
IB
I1
I1
I2
What do you notice about all of the amps?
_________________________________
_________________________________
A total of _______ Volts leaves the battery.
All of the energy is used up as it moves
through the circuit, so VB = V1 +_ V2 + V3
Page 5
Electrons only have one path to flow in
a series circuit, therefore if one flows
fast, the rest have to flow fast. If one
flows slow, the rest must flow slow.
Therefore, current is constant.
I B = I 1= I 2
Electricity Hands-On #4 – Voltage and Amperage
Parallel
To measure the voltage the meter must be placed around the load.
Measuring amps must be done in series behind a load.
Load Being Tested
VB
Volts
Use this diagram for
each test
Teacher
Signature
VB
V1
V1
V2
V2
What do you notice about all of the Volts? ___________
______________________________________________
Current being tested
Amps
Teacher
Signature
IB(out)
IB (out)
IB(in)
IB (in)
I1
I1
I2
I2
I1
When in parallel, both paths get equal amount
of energy (Joules per Coulomb)
VB = V1 = V2
Show math:
Page 6
+ I2 = ______________ . Is this close to IB ? ______
If the flow of electrons splits in
to two paths, each path has less
flow. When the paths meet back
together the flow becomes full
again.
Show Work:
IB (out) = IB (in)
IB = I1 + I2
Electricity Hands-On #5 –Amperage with Parallel Batteries
Complete the following circuit and determine the appropriate Amperage for each. Use a Christmas
bulb light for the R **Notice – all 3 set-ups are the same except for where the ammeter is placed
+
A
+
A
R
R
+
-
+
-
B
B
Circuit A
Circuit C
A
R
B
Teacher Signature
Circuit B
Current
Switch Setting
Switch A
Switch B
Closed
Open
Open
Closed
Closed
Closed
Circuit A
Ammeter Reading
Circuit B
Circuit C
What is the Ammeter reading current of in A? ___________________________
What is the Ammeter reading current of in B? ___________________________
What is the Ammeter reading current of in C? ___________________________
Page 7
Electricity Hands-On #6 – Creating a Motor
Before connecting the last wire, set up the circuit as shown and make sure the coil is balanced and
free to spin.
Keep the circuit open and flick the coil with your fingertip to start it spinning. Record what
happens in the data table below.
Close the circuit and again flick the coil. Again record observations.
Draw the circuit
Teacher
Signature
Open Circuit
Observations
Closed Circuit
Observations
Use the multimeter to measure amps and volts. Use Ohm’s Law to calculate the resistance of the
motor.
Show work:
Amps = ______
Volts = ______
Resistance = ________________
Indicate the charges placed on the coil of wire when a current is passing through it? (Remember
Lab #2 with the Galvanometer).
The magnet is placed below it. Indicate the charge on the magnet if the coil is trying to push away
from it.
Page 8
Electricity Lab Pack
Circuits
Name:
Period: