Question

Choose the correct option:
The gold leaves of a gold-leaf electroscope are enclosed in a glass bottle-
(A) to protect the gold leaves from drafts of air.
(B) to protect the gold leaf from rusting.
(C) to protect the gold leaves from wear and tear.
(D) All of the above.

Answer 1

Hint
A gold leaf electroscope is an instrument used for detecting the presence of an electric charge on a body. Sometimes, the wind creates errors in the observation. So, the glass-wall chambers are usually open at the bottom and mounted over a conductive base.

Complete step by step answer
 The gold leaves of a gold-leaf electroscope are enclosed in a glass bottle to protect the gold leaves from drafts of air. If we don’t, the wind creates errors in the observation.
They are typically enclosed in a glass bottle or glass-wall chamber. These are usually open at the bottom and mounted over a conductive base. There are often the grounded metal plates (or, foil stripes) in the bottle flanking the gold leaves on either side.
A gold leaf electroscope is an instrument used for detecting the presence of an electric charge on a body and its relative amount. This electroscope is usually made up of a metal plate or sphere at the top of an electrode. The thin strips of gold leaves hang from the bottom of that electrode. Now, when the electrode is given a charge by induction, the gold leaves acquire a similar amount of electric charges and start repelling each other due to the Coulomb force. Their separation or the extent to repel each other indicates the net charge stored in them.

Note
It is necessary to note that if an excessive charge is applied to the gold leaves, they will touch the grounding plates and will get discharged. As they capture charge leaking through the air it increases the sensitivity of the device.