To investigate the variation of current ( I ) with pd ( V ) for a filament bulb
When a voltage source is connected across a filament bulb a current flows through the filament causing it to get hot and emit light.
In this experiment we investigate how the current flowing through the filament varies with different voltages applied to it.

- Note that current is 0 when voltage is 0. Record the voltage and current results in a table.
- Click on the slider to increase the voltage from the potentiometer.
- Record the voltage and current readings from the voltmeter and ammeter.
- Repeat steps 2 and 3 until you have at least six sets of readings.

**Analysis:**

Draw a graph of current (y-axis) against voltage to find the relationship between them. Note: Start both axes at zero.

Be sure you understand and can explain why current does not continue to increase in a constant manner as voltage is increased.