Question

A polythene piece rubbed with wool is found to have a negative charge of $3.6\times {10}^{-7}C.$ Calculate the number of electrons transferred from wool to polythene:

• A. $6.25\times {10}^{18}$
• B. $2.25\times {10}^{12}$
• C. $2.05\times {10}^{-18}$
• D. $2.18\times {10}^{10}$

Answer 1

The correct option is B $2.25\times {10}^{12}$

$n=\frac{q}{e}=\frac{-3.6\times {10}^{-7}C}{-1.6\times {10}^{-19}C}$

$=2.25\times {10}^{12}$
$\therefore 2.25\times {10}^{12}$ electrons are transferred from wool to polythene.