School of Physics Lecture Demonstration Manual

El-1 Charging by Induction

Published: Tuesday 14 March 2006 - Updated: Thursday 31 March 2011

Aim

To charge an electroscope by induction.

Apparatus

Diagrams

Click on pictures to enlarge.

Charge By Induction Apparatus

Charging By Induction Diagram

Videos

Charge By Induction

Direct Charge Transfer

Description

The charging rod is charged negatively by rubbing it with the cats fur (a flicking motion is found to work best). The rod is brought near the cap of the electroscope whose leaves diverge indicating potential. The cap of the electroscope is now earthed by touching it while the charged rod is still near it. Electrons will flow to earth. The earth connection and the charged rod are removed in that order, leaving a nett positive charge on the electroscope.

Safety notes

Electrical safety 

Maintenance 

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