Uses of the electroscope
a) To distinguish between a conductor and an insulator.
When a conductor is brought into contact with a charged electroscope, the leaf falls. When the electroscope is positively charged, electrons flow from the earth through the material to the electroscope to neutralize the positive charges. When the electroscope is negatively charged, electrons flow through the material to the earth. Hence the leaf falls.
However, for an insulator there will be no effect on the leaf divergence of the electroscope.
b) To test the quantity of charge on a charged body.
The degree of leaf divergence is proportional to the quantity of charge on a body i.e. the higher the quantity the larger the divergence.
c) To detect the presence of charge on a body.
When a charged body is brought close to the cap of an electroscope, the behavior of the leaf will determine whether the body is charged or not. This will be looked at in the next point. However, when an uncharged body is brought close to the cap of a charged electroscope; either positively or negatively, the leaf divergence reduces while if the electroscope is uncharged, they will be no effect on the leaf divergence.
d) To test the sign of the charge on a charged body.
If a charged body is brought near the cap of a charged electroscope, the leaf of the electroscope will diverge more if the body and the electroscope have similar charges and the leaf divergence will decrease if the two have different charges.
johnmulu answered the question on February 7, 2017 at 07:25
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