Q. Eight drops of mercury of equal radii possessing equal charges combine to form a big drop. Then the capacitance of bigger drop compared to each individual small drop is
A) 8 times
B) 4 times
C) 2 times
D) 32 times
Explanation
(c) Volume of 8 small drops = Volume of big drop
$8 \times \frac{4}{3}\pi r^{3} = \frac{4}{3}\pi R^{3} \Rightarrow R = 2r$
As capacity is proportional to $r,$ hence capacity becomes 2 times
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.