Workout: The capacitor


Two parallel sheets of charge and the capacitor.


the PhET simulation Capacitor lab.

Set up

Slide the slider on the battery up to the maximum (+1.5 V). Make sure "plate charges" is checked. Your screen should look like the figure below.

Answer these questions

1. Turn on the voltmeter. This measures the voltage difference between the two probes. Does it subtract the value on the red probe from the black or the other way around? How would you test that?

2. Test the voltage difference between the top plate of the capacitor and the bottom plate. What is it? Explain why it has the value you found.

3. Now turn off the voltmeter and turn on the electric field detector. Where do you find non-zero values of the electric field? When you find it, what direction does it point? Explain why this is so.

4. Turn on the plate charge meter, showing the charge on the top (red is +, blue is -). Change the voltage slider on the battery and explain what you see.

Dave Buehrle, Fall 2016

Article 653
Last Modified: April 30, 2019