Faraday's Cage and Braun Electroscope
Faraday's Cage and Braun Electroscope

 

Code Number: 5B20.30

Demo Title: Faraday's Cage - Electroscope

Condition: Good

Principle: Electrostatics

Area of Study: Electricity & Magnetism

Equipment: 

Faraday's Cage and Braun Electroscope.

Procedure:

Put the electroscope  inside the Faraday's cage. No charging of the electroscope should be observed when the Van de Graaff is turned on.

You may also use a flexible mesh screen for a simpler form of this demonstration. Stretch the screen between two poles and place aluminum "leaves" on both sides of the screen. Charge the screen, the "leaves" will deflect away from the screen, and then bring the two ends together forming a cylinder. The "leaves" on the inside of the cage should go down while the ones on the outside go up or out. Retry the experiment but twist one end so you make a Möbius strip and observe the "leaves".

References:

  • Joon Hee Hong and Jung Bog Kim, "Demonstration of a Faraday Cage Using a Metal Leaf Electroscope", TPT, Vol. 57, #5, May 2019, p. 334.
  • Seán Stewart, "Flexible Faraday Cage with a Twist: Surface Charge on a Möbius Strip", TPT, Vol. 45, #5, May 2007, p. 268.
  • Paul Gluck, "The Flexible Faraday Cage", TPT, Vol. 42, #3, Mar. 2004, p. 181.
  • Jim Hicks and Chris Chiaverina, "The Authors Reply", TPT, Vol. 23, #2, Feb. 1985, p. 126.
  • R. Dollinger, W. J. Sarjeant, J. R. Laghari, D. Dettman, M. Nikolich, John Shea, Marianne Rickley, and Michael Belling, "But is it Safe?", TPT, Vol. 23, #2, Feb. 1985, p. 70, 126.
  • Mario Iona, "Not Really Shocking", TPT, Vol. 23, #2, Feb. 1985, p. 70.
  • Chris Chiaverina, "A Faraday Ice Pail Convincer", TPT, Vol. 22, #8, Nov. 1984, p. 531.
  • Freier and Anderson, "Ea-20", A Demonstration Handbook for Physics.
  • Julien Clinton Sprott, "4.7, Faraday Cage", Physics Demonstrations, ISBN 0-299-21580-6, p. 197.
  • Jearl Walker, "5.3, Lightning: Vehicles", The Flying Circus of Physics Ed. 2, p. 220.
  • Robert Ehrlich, "O.6, Shielding a Radio", Turning the World Inside Out and 174 other Simple Physics Demonstrations, p. 174.
  • Brian Jones and Matt Fackelman, "Radio Shack - Stopping Electromagnetic Waves", Don't Forget the Duct Tape - a Little Shop of Physics Publication, p. 97.
  • Rudolf F. Graf, "Shielding Your Electroscope", Safe and Simple Electrical Experiments, p. 18.
  • Borislaw Bilash II, “Faraday's Cage“, A Demo A Day – A Year of Physical Science Demonstrations, p. 280.
  • Julius Sumner Miller, Q221 & A221, Millergrams II – Some More Enchanting Questions for Enquiring Minds, p. 68 & 116.
  • The Queen Catalogues Vol. II, Catalogue of Physical Instruments, p. 76.
 
5B20.30 Van de Graaff Electroscope
5B20.30 - University of Maryland QOTW #186
5B20.30 - University of Maryland QOTW #189