I-V characteristics

Investigate the I−V characteristics of a variety of circuit elements including a filament lamp, a resistor and a diode at constant temperature.

Materials

Set up circuits with different sets of equipment to investigate how the current changes as with the potential difference.

 

There are three parts to this investigation:

•  characteristics of a lamp

•  characteristics of a resistor

•  characteristics of a diode.

Method

1.  Record the current through each component for different values of potential difference.

This method uses a variable resistor to vary the potential difference, although a variable power supply may be used instead.

2.  Plot a graph of current against potential difference.

The shape of the line/ curve of best fit indicates the characteristics of the component.

 

Note: The resistance at any point on the graph is the inverse of the gradient of a line from that point to the origin.

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