Question
A capacitor of capacitance $C$ is charged to a potential difference $V$ from a cell and then disconnected from it. A charge $+Q$ is now given to its positive plate. The potential difference across the capacitor is now $Q$

 if $V < CV$

Answer

After redistribution half of total charge remains on outer surface and then apply

conservation of charge on each plate.

Charge on outer plates $=\frac{Q+C V-C V}{2}=\frac{Q}{2}$

Charge of innerface of first plate,

$=Q+C V-\frac{Q}{2}=\frac{Q}{2}+C V$

Charge on innerface of second plate $=-\left(\frac{Q}{2}+C V\right)$

$V^{\prime}=\frac{Q / 2+C V}{C}=V+\frac{Q}{2 C}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In given compounds which one does not give silver mirror test ?
The vernier scale used for measurement has a positive zero error of $0.2\, mm$. If while taking a measurement it was noted that $'0'$ on the vernier scale lies between $8.5\, cm$ and $8.6\, cm$ vernier coincidence is $6,$ then the correct value of measurement is ............. $cm$. (least count $=0.01\, cm )$
The extension of a wire by the application of load is $3$ $mm.$ The extension in a wire of the same material and length but half the radius by the same load is..... $mm$
The wavelength of most energetic $X-$ rays emitted when a metal target is bombarded by $40KeV$ electrons, is approximately.......$\mathop A\limits^o $

($h = 6.62 \times {10^{ - 34}} J-sec; 1 eV = 1.6 \times {10^{ - 19}}J; c = 3 \times {10^8}\,m/s)$

The displacement-time graphs of two moving particles make angles of $30^{\circ}$ and $45^{\circ}$ with the $x$-axis as shown in the figure. The ratio of their respective velocity is :
A body of mass ${m_1}$ moving with a velocity$ 3 ms^{-1}$ collides with another body at rest of mass ${m_2}.$After collision the velocities of the two bodies are $2 ms^{-1} \,and \, 5ms^{-1}$ respectively along the direction of motion of ${m_1}$ The ratio $ \frac{m_1}{m_2}= $ 
If the temperature of the body is increased by $10\% $ , the percentage increase in the emitted radiation will be ....... $\%$
A $3.0\; cm$ wire carrying a current of $10 \;A$ is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be $0.27\; T$. What is the magnetic force on the wire?
$A$ current $I$ flows through a uniform wire of diameter $d$ when the mean electron drift velocity is $V$. The same current will flow through a wire of diameter $d/2$ made of the same material if the mean drift velocity of the electron is :
In $a$ series $R-L-C$ circuit, the frequency of the source is half of the resonance frequency. The nature of the circuit will be