Question

Suppose you have a glass rod which becomes positively charged when you rub it with wood. Describe how would you charge the electroscope,
(i) negatively
(ii) positively

Answer 1

Ans. CHARGING THE ELECTROSCOPE NEGATIVELY
In order to change the electroscope negatively, bring a positively charged rod near the disk of the electroscope. Negative charge will appear on the disk of the electroscope while positive charges will shift to the leaves. Now connect the disk of electroscope to the earthed aluminium foil by a conducting wire. Charge of the leaves will flow to the earth through the wire. Now if we first break the earth connection and then remove the rod, the electroscope will be left with negative charge.
connection and then remove the rod, the electroscope will be left with negative charge.