2. Questions Bank
  3. JEE Main & Advanced
  4. Physics
  5. Electrostatics & Capacitance

JEE Main & Advanced Physics Electrostatics & Capacitance Question Bank Grouping of Capacitors

  • question_answer
     A \[10\mu F\] capacitor and a \[20\mu F\] capacitor are connected in series across a \[200\ V\] supply line. The charged capacitors are then disconnected from the line and reconnected with their positive plates together and negative plates together and no external voltage is applied. What is the potential difference across each capacitor                                [MP PET 1997]

    A)            \[\frac{400}{9}\text{V}\]

    B)                             \[\frac{800}{9}V\]

    C)                    \[400\ V\]

    D)                                      \[200\,V\]

    Correct Answer: B

    Solution :

               Initially potential difference a cross each capacitor                    \[{{V}_{1}}=\frac{20}{(10+20)}\times 200=\frac{400}{3}V\]                    and \[{{V}_{2}}=\frac{10}{(10+20)}\times 200=\frac{200}{3}V\]                    Finally common potential \[V=\frac{{{C}_{1}}{{V}_{1}}+{{C}_{2}}{{V}_{2}}}{{{C}_{1}}+{{C}_{2}}}\]                    \[V=\frac{10\times \frac{400}{3}+20\times \frac{200}{3}}{(10+20)}=\frac{800}{9}V\]


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