How to detect nature of charge using gold leaf electroscope?
The nature of charge can be detected using a gold leaf electroscope as follows:
By touching the body to the brass disc: Let the electroscope be charged with positive charge. The leaves will be in diverged position. The body to be tested is touched with the brass disc of the electroscope and the divergence of leaves is observed.
Case (i): If the leaves diverge more, the body is positively uncharged. When the body touches the electroscope, its charges are transferred to the leaves. There is an increase in repulsion which happens due to increase in the same kind of charge, and hence, this indicates that the body is positively charged.
Case (ii): If the divergence of the leaves decreases, the body is negatively charged. When the body touches the electroscope, its charges are transferred to the leaves. There is a decrease in repulsion which happens due to decrease in the same kind of charge or increase in opposite kind of charge, and hence, this indicates that the body is negatively charged.