Q. If the circumference of a sphere is $2m,$ then capacitance of sphere in water would be
A) $2700\ pF$
B) $2760\ pF$
C) $2780\ pF$
D) $2800\ pF$
Explanation
(d) Given $2\pi R = 2 \Rightarrow R = \frac{1}{\pi}$
For sphere $C = 4\pi\varepsilon_{0}KR$
$\Rightarrow C = \frac{1}{9 \times 10^{9}} \times \frac{1}{\pi} \times 80\ \ \ \ \ $[For water $K = 80$]
$\Rightarrow C = 2828.28\ PF$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.