A polythene piece rubbed with wool is found to have a negative charge of $3 imes 10^{-7} ext{ C}$

Question

A polythene piece rubbed with wool is found to have a negative charge of $3 	imes 10^{-7}	ext{ C}$. Estimate the number of electrons transferred and from which to which material.

Professor PC Thomas Classes · Answer

Number of electrons $n = Q/e = 3 	imes 10^{-7} / 1.6 	imes 10^{-19} = 1.875 	imes 10^{12}$. Since polythene becomes negatively charged, electrons were transferred from wool to polythene.