RAJASTHAN PMT Rajasthan - PMT Solved Paper-2002

  • question_answer
    How many times, the potential of big drop in comparison to small drops which is made of 8 droplets will be, if all the droplets are identical?

    A)  2 times               

    B)         4 times

    C)  3 times               

    D)         8 times

    Correct Answer: B

    Solution :

    Volume of bigger drop = 8 x volume of small drops \[\frac{4}{3}\pi {{R}^{3}}=8\times \frac{4}{3}\pi {{r}^{3}}\]       \[R=2r\] Potential on small drop \[{{V}_{1}}=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{r}\] Potential on bigger drop                                 \[{{V}_{2}}=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{8q}{R}\]                                 \[\begin{align}   & =\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{8q}{2r} \\  & =4\left( \frac{1}{4\pi {{\varepsilon }_{0}}}\frac{q}{r} \right)=4{{V}_{1}} \\ \end{align}\] So, potential on the bigger is four times to that potential on small.


You need to login to perform this action.
You will be redirected in 3 sec spinner