Q. When a piece of polythene is rubbed with wool, a charge of -2$\times 10^{- 7}$ C is developed on polythene. What mass, is transferred to polythene?
A) 5.69$\times 10^{- 19}$ kg
B) 2.25$\times 10^{- 19}$ kg
C) 9.63$\times 10^{- 19}$ kg
D) 11.38$\times 10^{- 19}$ kg
Explanation
(d) Number of electric transferred, $n = \frac{q}{e}$
Mass transferred $= m_{e} \times n = m_{e} \times \ \left( \ \frac{q}{e} \right)$
$= 9.1 \times 10^{- 31} \times \left( \frac{2 \times 10^{- 7}}{1.6 \times 10^{- 19}} \right)$
$11.38 \times 10^{- 19}\ $kg
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.