Download Series Circuits

Electricity Web Simulations Day 2
Name
Date
Class
Circuit Construction Kit (DC Only) Simulation
In this simulation you will build circuits with resistors, light bulbs, batteries, and switches. Take measurements with the
ammeter and voltmeter. View the circuit as a schematic diagram, or switch to a life-like view.
Directions:

Click on circuit construction kit (DC only)

Click on Run Now.
Series Circuits
1. Simple Series Circuit- One Resistor
a) Construct a simple circuit that contains the following components: Light bulb, wire and a 10-V battery. Do not
use a resistor. See diagram to make sure
you have done this correctly. Pay careful
attention to the light bulb. Notice that there
are two small dotted circles on the light
bulb base. Each wire must connect to a
different circle.
b) Check off non-contact ammeter and
voltmeter under tools on the right side.
i)
Make sure that the components are in
series so you can trace a charge
traveling through the entire circuit from
the positive end of the battery to the negative end.
ii) Right-click the battery. Check the “Show Value” box it should read 10 V. If not correct
iii) Right-click the light bulb. Check the “Show Value” box it should read 10 Ω. If not correct.
c) Use the voltmeter to confirm that the voltage of the battery is in fact 10 volts. Do this by placing the red probe
on the battery where the electrons enter and the black probe on the side where the electrons exit the battery. If
it is not 10 volts, change it by right-clicking the battery and using the keyboard to enter in 10V.
d) Record the current flowing through the circuit by reading the ammeter value:
e) Use Ohm’s Law to predict the resistance of the light bulb. Show work in space provided:
Rbulb =
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Electricity Web Simulations Day 2
f) Confirm this resistance by right clicking on the light bulb and then clicking the “Change Resistance” button. You
should see the resistance listed on the screen.
g) Was Ohm’s Law verified here?
Why or why not?
2. Simple Series Circuit- Two Resistors
a) Add another light bulb in series to the simple circuit above. To do this right click on one of the gray circles
where a wire connects and select split junction. Then add additional light bulbs and wire as needed.
b) Right click both light bulbs to make sure they are 10-Ω light bulbs.
c) Confirm that the battery is still 10-volt using the voltmeter.
d) Determine the current flowing through the circuit by hovering the non-contact ammeter over the wire. Record
the ammeter reading here:
e) In a series circuit the total resistance is sum of the resistance of ALL the light bulbs. Based on that fact
determine the total resistance of the 2 light bulb circuit. Rtotal =
f) Add a third light bulb to the circuit by connecting it in series to the others. Repeat steps b through e and
calculate the total resistance of the 3 bulbs. Record this resistance here: Rtotal =
g) What is the formula for equivalent resistance in a series circuit?
Now stop using the computer and solve the following 4 questions. Show all work in the space below the
question.
1. Using Ohm’s Law, calculate the current I flowing through
the circuit in diagram to the right. Show work in the
space provided.
I=
2. What is Req for the circuit in Figure to the left?
3. Using Ohm’s Law and your value for Rtotal calculate the current
I flowing through the circuit. Show work in the space provided.
I=
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Electricity Web Simulations Day 2
4. How could a resistor be used to prevent a 4-Ω car speaker from blowing out due to too much current?
Parallel Circuits vs. Series Circuits
1. Build a Series Circuit
a) Build a circuit with one 10 ohm (Ω) light bulb and a 10 volt battery.
b) Place an ammeter where the current leaves the battery.
i)
Record the value here: ________
c) Now put a second light bulb in series with the first light bulb.
i)
Record the new current here: ________
d) Using what you learned in the previous simulation about total resistance, determine the total resistance for this
circuit. Record the total resistance of the circuit here: _______
e) Note how bright each light bulb is when in series by developing your own brightness scale. Rank the
brightness of your bulbs on a 1-10 scale. Record the ranking here: ________
Clear your screen.
2. Build a parallel circuit
a) Now build a parallel circuit with a 10 volt battery and two 10 ohm light bulbs.
b) See the diagram to the right for how to set this up.
c) Record the brightness of the light bulbs using the same
brightness scale as before.
d) Place an ammeter where the current leaves the battery.
i)
Record the value here:
e) Place an ammeter in each branch next to the light bulb.
i)
Record the first value here:
ii) Record the second value here:
f) What do you notice about the current in each branch compared to the current leaving the battery?
g) What do you notice about the total current as it leaves the battery in series as compared to when it leaves the
battery in parallel? Is this a good or a bad thing?
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Electricity Web Simulations Day 2
Comparing the 2 types of Circuits
h) Were the light bulbs brighter when wired in series or parallel?
i)
Is the current leaving the battery bigger when the bulbs are wired in series or in parallel?
j)
If the current is bigger, according to Ohm’s law the resistance is smaller. Is the resistance bigger in a series or
parallel circuit?
3. Parallel Circuits Further Investigations
a) Now change the resistance of one of the light bulbs to 20 ohms.
i)
Record the total current leaving the battery here:
ii) Record the current in the 20 ohm branch here:
iii) Record the current in the 10 ohm branch here:
b) Which light bulb got more current?
Why?
c) What do you notice about the current in each branch compared to the current leaving the battery?
d) Which light bulb is brighter?
Why?
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