JEE Mains · Physics · STD 12 - Electric potential and capacitance
- JEE Mains 2023
- Medium
- Numerical
\(64\) identical drops each charged upto potential of \(10\,mV\) are combined to form a bigger dorp. The potential of the bigger drop will be \(..........\,mV\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(160\)
Step-by-step Solution
Detailed explanation
Let \(q =\) charge on each drop
\(V =\frac{ Kq }{ r } \text {-.- (1) }\)
Now for combination of 64 drop
\(64 \times \frac{4}{3} \pi r^3=\frac{4}{3} \pi R^3\)
\(R=4 r\)
And \(Q =64 q\)
Potential of bigger drop
\(=\frac{ KQ }{ R }=\frac{ K 64 q }{4 r }=16 \frac{ Kq }{ r }\)
\(=16 \times 10\,mV =160\,mV\)
Correct answer is \(160 .\)
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