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How to Determine Which Electroscope Has More Charge

An electroscope is a device that detects electrical charges. It consists of a glass case with a conducting plate on top. A metal rod connected to the conducting plate hangs inside the case and two pieces of gold leaf at the end of the rod react to electrical charges. The amount of the charge is either read on a scale of degrees on the front of the case using a protractor or by estimating the angle of the gold leaves relative to their neutral position. You can determine which electroscope has more charge.

Things You'll Need

2 gold leaf electroscopes
Grounding plate, properly grounded
Small piece of fur
2 amber rods
Protractor (optional)

Instructions

- 1
  Remove the excess charges from the electroscopes by touching the grounding plate to the conducting plate. Excess electrons will flow into the grounding plate and through a wire attached to a stake in the ground in a process called grounding. Alternatively, you can touch the conducting plate with your finger and your body will conduct the charge to the ground.
- 2
  Verify that the electroscopes are balanced (neutral). The gold leaves should hang straight down to the 0-degree mark.
- 3
  Induce a charge on one of the amber rods by repeatedly rubbing it in the same direction with the fur. Hold the rod close to one of the conducting plates, but do not touch the plate. The excess electrons from the induced charge on the amber rod will repel the free electrons of the conducting plate and the rod inside the electroscope. They end up in the gold leaves, causing the leaves to rise away from the rod.
- 4
  Touch the conducting plate with your finger while still holding the amber rod near the plate. Remove your finger and the amber rod to balance (neutralize) the charge the conducting plate.
- 5
  Repeat Steps 3 and 4 on the second electroscope with the remaining amber rod. Keep the electroscopes far enough away from each other that the charges do not interfere with one another.
- 6
  Read the scales on the front of the electroscopes to find the amount of the charge. Alternatively, measure the angle of the gold leaves with a protractor or visually estimate the position of the gold leaves. Compare the readings of the two electroscopes to determine which one has the most charge.

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