Q. Charges 5$\mu$C and 10$\mu$C are placed 1 m apart. Work done to bring these charges at a distance 0.5 m from each other is
A) $9 \times 10^{4}$ J
B) $18 \times 10^{4}$ J
C) $45 \times 10^{- 2}$ J
D) $9 \times 10^{- 1\ }$ J
Explanation
(d) Given, $q_{1} = 5\mu C,\ q_{2} = 10\mu C$
and $r = 0.5$ m
$\ \ \ W = \frac{1}{4\pi\varepsilon_{0}k}\frac{q_{1}q_{2}}{r}$
$= 9 \times 10^{9} \times \frac{5 \times 10^{- 6} \times 10 \times 10^{- 6}}{0.5}$
$= 9 \times 10^{- 1}\ $J
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.