Objectives:

• To be able to define resistance
• To be able to select and use the equation for resistance  $R = \frac{V}{I}$
• To state and use Ohm’s law
• To describe the I–V characteristics of a resistor at constant temperature and a bulb where the temperature varies (the bulb will largely will covered in the next lesson)

Resistors serve a vital role in electronic circuits, and that is to limit the amount of current flowing through the circuits.

The larger the resistance the stronger resistance there is to the flow of electrons.

During this lesson you will have worked on trying to investigate the difference between a number of different unknown resistors. In order to do this we set up the diagram as shown below;

For each resistor placed in the circuit, the voltage supplied was varied and a number of results were recorded.

The following is a document showing these results which can be used for your some practice if you did not record a sufficient amount of data.

Class data set for experiment on Resistors (click here)

If you have any queries regarding the how to work out the resistance column then read through the previous lessons notes or please leave a comment.

Further reading:

• You should research how overhead transmission cables are constructed and the reasons behind the material choice.
• You should research into the discovery and onset of superconductivity and the potential benefits of room temperature superconductors.