Electrostatics Question 50
Question: Two metallic charged spheres whose radii are 20$ cm $ and 10$ cm $ respectively, have each 150$ micro-coulomb $ positive charge. The common potential after they are connected by a conducting wire is [MP PMT 1991]
Options:
A) $ 9\times 10^{6}\ volts $
B) $ 4.5\times 10^{6}\ volts $
C) $ 1.8\times 10^{7}\ volts $
D) $ 13.5\times 10^{6}\ volts $
Show Answer
Answer:
Correct Answer: A
Solution:
Common potential $ V=\frac{\text{Total charge }}{\text{Total capacitance}} $
$ V=\frac{150\times {{10}^{-6}}\times 2}{4\pi {\varepsilon _{0}}(10\times {{10}^{-2}}+20\times {{10}^{-2}})}=9\times 10^{6}V $
