Category Archives: Electrostatics

Electrostatic Twirl

Demo Code: EM-A-ET
Pira Index: 5A 20.10

Video link: Electrostatic twirl

Lab Equipment Direction
1. 3 PVC pipes (exactly alike)

2.  Lab Stand

3.  String

4. Short lab Pole

5. 90 degree clamp

6. Paper towel

7. Plexiglass charging rod (same size as PVC)

1.  Suspend one PVC pipe on a string as shown and loop the straight string over the lab pole. 2.  Charge the suspended pipe by rubbing it with paper towel.3.  Charge another pipe and bring it near the suspended one. Observe.

4.  Charge the 3rd pipe and bring 2 charge pipes near the suspended one. Compare the effect of two pipes with the effect of only one pipe.

5. Charge the acrylic rod w/the paper towel and watch it attract the hanging PVC pipe.

Popcorn Popper

Demo: EM-B-PP
Pira Index: 5B 10.30

  1.  Popcorn popper
  2. PVC plate (gray plate)
  3. Rabbit fur
  1.  Rub the fur back and forth against the PVC until it acquires a charge.
  2. Place the metal pan with the Styrofoam handle on the plate; touch the edge of the pan with your finger.
  3. Pick up the plate by the Styrofoam handle and place it on top of the popper.
  4. Repeat step 2 and 3 several times. The “popcorn” should then begin popping.

Option – Popper can be set on top of Van de Graaff instead of using the charging box.


Van de Bubbles

Demo: EM-A-VB
Pira Index: 5A 40.24

  1.  Van de Graaff
  2. Insulating platform
  3. Soap bubble solution
  1.  Turn on Van de Graaff and stand on the platform
  2. Blow bubbles over the top of the Van de Graaff. Watch as like charges repel the soap bubbles away from the Van de Graaff.
  3. Have a student place their hand above a charged bubble. The bubble lifts up towards the student’s hand.


Scotch Tape Induction

Demo: EM-A-TI
Pira Index: 5A 10.00

  1. Electroscope (large)
  2. Vise with round metal plate
  3. Clip lead A-B
  4. PVC platform (1′ square)
  5. Clear packing tape 2″ wide
  6. Maglight
  7. Lens holder and base
  8. Screen
  1. Set up a shown below.
  2. Rub tape strips onto round plate then pull off tape without touching the metal plate. Tap the electroscope if needle sticks. The needle shows static charge.
  3. Bring the 2 tape strips near each other and they repel (like charges).
  4. Place tape strips one on the back of the other then rub them onto the plate. Pull them off and separate. Note that the strips now attract.


Rotating 2 x 4

Demo: EM-A-RO
Pira Index: 5A 40.30

  1.  Large watch
  2. 2″ x 4″ x 72″ wooden beam
  3. Styrofoam electroscope (doll)
  4. Fur and silk
  5. Static rods
  1. Balance the beam on the large watchglass.
  2. Rub the fur or silk on the rod to charge the rod.
  3. (A) Hold the rod near the end of the block of wood so that the rod is close to and parallel to the side of the block.
  4. (B) Hold the rod near the ends of the arms of the styrofoam electroscope.


Positive and Negative Electrophorus

Demo: EM-A-PN
Pira Index: 5A 10.20

  1. Acrylic plate and charge disk with handle
  2. PVC plate and charge the disk with handle
  3. Paper towel
  4. Electroscope

  1.  Rub paper towel across acrylic to charge plate positively. Set charge disk on plate and touch metal disk with your finger. Lift disk (now negatively charged) by handle. Touch disk to knob of electroscope.
  1. Rub paper towel over PVC plate to charge plate negatively and set charge disk on plate. Touch metal disk with your finger. Disk is now charged positively. Bring disk (positively charged) near the negative charged electroscope (from step 1). Electroscope should show discharge.


Pepsi Can Electrode

Demo: EM-A-PE
Pira Index: 5A 20.28

  1.  Two empty soda cans on strings and two coated ping pong balls on strings
  2. Lab stand with PVC cover for insulation
  3. Short rod with 90 degree clamp
  4. 90 degree with short piece of rubber hose
  5. PVC rod and paper towel
  6. Electrophorus (Acrylic plate (clear) and aluminum disk with cup for handle)
  1.  The two cans and two ping pong balls hang from the horizontal rod.
  2. Charge the electrophorus with the paper towel: (rub paper towel across acrylic to charge the place positively. Set charge disk on plate, touch metal disk with your finger. Lift disk, now negatively charged, by handle. Touch disk to cans).
  3. Charge the PVC rod with paper towel and bring it near the cans. Watch the can separate.
  4. The experiment can be repeated with the ping pong balls.The PVC on the rod can be charged using the paper towel to reduce the cans attraction to the support rod.