You can see how an electroscope can be charged by induction by watching "Inductive Charging using an Electroscope" Video


Read Charging Objects by Induction
The most complex method of giving an object a charge is charging by induction. You can learn more about this procedure by reading "Charging Objects by Induction" on pages 520 and 521 of your textbook. After complete Self Check 1-3.



Charging by Induction: the process of charging whereby a primary charged object is brought close to a secondary neutral object, polarizing the secondary object. The secondary object is grounded either allowing electrons to leave or to enter. The ground is removed and then primary charged objected is removed. This results in the secondary object be charged oppositely to the primary object.



Define induction

Induction is the movement of charge due to the presence of another external object that is charged.


The link Induction with a Negative Source shows a negative source charging an electroscope by induction. Write a concise description or illustrate with labels to explain what is occurring during each step of this process.

  1. The negative object is brought next to a neutral electroscope.

  2. The external negative object repel the negative charges in the electroscope down to the leaves. Since the leaves become negatively charged, they repel one another and separate.

  3. The electroscope being grounded on the opposite side of the external negative source. The excess electrons on the external negatively charged rod repel the electrons in the electroscope. Therefore, some of the electrons in the electroscope escape to the ground.

  4. The ground connection is removed. The leaves come closer together as the leaves are no longer as negatively charged as they once were.

  5. The external negative object is removed. The remaining electrons on the electroscope redistribute. Since some of the electrons were transferred to the ground in the third step, the electroscope is now positively charged. Since the leaves become positively charged, they repel one another and separate.


Sketch a series of diagrams to show how a negative source could charge an electroscope by induction. Write a concise description or illustrate with labels to explain what is occurring during each step of this process.