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Physics
Electricity and Heat
Sensors:
Loggers:
Current
Any EASYSENSE
Logging time: SnapShot
26 Good and bad conductors
Read
The size of the current in a circuit depends on the number of cells it contains. In this experiment, you will see
that the material a circuit is made up of will also affect the size of the current.
A conductor is a material that will allow an electrical current to pass through or flow easily through it. Copper
is a good conductor of electricity and is commonly used in electrical wiring. The human body is also a good
conductor of electricity.
As well as having materials that conduct electricity there are materials that do not conduct electricity very
well. These are called insulators; they allow very few electrical charges to flow and act as a barrier to
electricity. Electrically insulating materials are used to coat copper conducting wires. Electrical insulators help
to protect humans from coming into contact with electricity flowing through conductors. Insulators are also
used to control where electricity can flow or how quickly it will flow.
What you need
1.
2.
3.
4.
5.
6.
An EASYSENSE logger.
A Smart Q Current sensor
Resistor
2 x 1.5 V cells in a holder
Connecting wires
A variety of materials to test.
_
Resistor to protect Sensor
Current Sensor
Note: Be careful when handling the test materials after they have been in the circuit. Some of them may
become hot.
What you need to do
1. Connect the Current sensor to an input of the logger.
2. Assemble the apparatus as shown. Make sure the coloured wires from the Current sensor are
connected the right way - the black lead should go back to the negative (-) terminal of the cell holder
and the red lead to the positive (+) terminal.
3. From the EasySense software’s Home screen select SnapShot.
Electricity and Heat
26 - 1 (V2)
4. Click on the Start icon to begin logging. With none of the test materials in circuit, click in the graph
area to take the first reading. Double click in the Comments column alongside the reading and type
'nothing' in the dialogue box.
5. Connect the first material to test into the circuit. Click in the graph area to take a reading. Type the
name of the material into the comments column.
6. Repeat for all of the other test materials.
7. Click on Stop to finish recording.
Results and analysis
Add a Title to the graph and then Save the results. The results can be printed or copied into your report
document as required.
Questions
1. List the materials tested in order from best to worst conductor.
2. Which materials do not seem to pass any current?
3. Which material would you use for electrical wiring? Explain your choice e.g. what else might you
consider apart from the ability to conduct electricity.
4. Does it make any difference which way around the material is connected?
5. Why do some connectors to audio and video systems have gold plated connectors?
Electricity and Heat
26 - 2 (V2)