The plates of a parallel plate condenser are pulled apart with a velocity $v$. If at any instant their mutual distance of separation is $d$, then the magnitude of the time of rate of change of capacity depends on $d$ as follows
Diffcult
Download our app for free and get startedPlay store
(b)$C = \frac{{{\varepsilon _0}A}}{x};$ 

$\frac{{dC}}{{dt}} = {\varepsilon _0}A\frac{d}{{dt}}\left( {\frac{1}{x}} \right)$$ = \frac{{ - {\varepsilon _0}A}}{{{x^2}}}\left( {\frac{{dx}}{{dt}}} \right) = \frac{{ - {\varepsilon _0}A}}{{{d^2}}}\left( {\frac{{dx}}{{dt}}} \right)$
$==>$ $\left| {\frac{{dC}}{{dt}}} \right| = \frac{{{\varepsilon _0}A}}{{{d^2}}}v$ i.e. $\left| {\frac{{dC}}{{dt}}} \right| \propto \frac{1}{{{d^2}}}$

art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    Five similar condenser plates, each of area $A$, are placed at equal distance apart and are  connected to a source of $e.m.f.$ $V$ as shown in the following diagram. The charge on the  plates $1$ and $4$ will be:-
    View Solution
  • 2
    A slab of dielectric constant $K$ has the same crosssectional area as the plates of a parallel plate capacitor and thickness $\frac{3}{4}\,d$, where $d$ is the separation of the plates. The capacitance of the capacitor when the slab is inserted between the plates will be.(Given $C _{0}=$ capacitance of capacitor with air as medium between plates.)
    View Solution
  • 3
    $64$ small drops of mercury, each of radius $ r$ and charge $q$ coalesce to form a big drop. The ratio of the surface density of charge of each small drop with that of the big drop is
    View Solution
  • 4
    Two concentric spheres $A$ and $B$ are kept very near to each other. $A$ is negatively charged and $B$ is earthed. The true statement is

    $(A)$ Charge on $B$ is zero

    $(B)$ Potential at $B$ is zero

    $(C)$ Charge is uniformly distributed on $A$

    $(D)$ Charge is non uniformly distributed on $A$

    View Solution
  • 5
    A capacitor stores $60\,\mu C$ charge when connected across a battery. When the gap between the plates is filled with dielectric, a charge of $120\,\mu C$ flows through the battery. The dielectric constant of the dielectric inserted is
    View Solution
  • 6
    In the figure shown below, the charge on the left plate of the $10\, \mu F$ capacitor is $-30\,\mu C.$ The charge on the right place of the $6\,\mu F$ capacitor is.....$\mu C$
    View Solution
  • 7
    Two dielectric slabs of constant ${K_1}$ and ${K_2}$ have been filled in between the plates of a capacitor as shown below. What will be the capacitance of the capacitor
    View Solution
  • 8
    $STATEMENT-1$ For practical purposes, the earth is used as a reference at zero potential in electrical circuits.and

    $STATEMENT-2$ The electrical potential of a sphere of radius $R$ with charge $\mathrm{Q}$ uniformly distributed on the surface is given by $\frac{\mathrm{Q}}{4 \pi \varepsilon_0 R}$.

    View Solution
  • 9
    The expression for the capacity of the capacitor formed by compound dielectric placed between the plates of a parallel plate capacitor as shown in figure, will be (area of plate $ = A$)
    View Solution
  • 10
    A $12\,pF$ capacitor is connected to a $50\,V$ battery. How much electrostatic energy is stored in the capacitor
    View Solution