Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
0 votes

125 drops of water of same radius and same charge combine to form a big drop. Ration of potential of big drop to the potential of small drop.

$(A)\;25 \\ (B)\;\frac{1}{25} \\ (C)\; 1 \\ (D)\;125 $

Can you answer this question?

1 Answer

0 votes
Potential on small drop (V) $=\large\frac{1}{4 \pi \in _0} \frac{q}{r}$
Volume of 125 small drops = Volume of big drop
=> $125 \times \large\frac{4}{3} \pi r^3= \large\frac{4}{3}$$\pi R^3$
=> $ R= 5r$
Potential on big drop,
$V'= \large\frac{1}{4 \pi \in _0} \frac{Q}{R}$
$\quad= \large\frac{1}{4 \pi \in _0} \frac{125 q}{5r}$
$\quad=25 V$
Hence A is the correct answer.


answered Jan 8, 2014 by meena.p
edited Jul 31, 2014 by thagee.vedartham
Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App