$27$ identical drops are charged at $22\, V\,\,each.$ They combine to form a bigger drop. The potential of the bigger drop will be............ $V.$
JEE MAIN 2022, Medium
Download our app for free and get startedPlay store
$q \rightarrow nq$

$n \frac{4}{3} \pi r ^{3}=\frac{4}{3} \pi\left( r ^{\prime}\right)^{3}$

$\Rightarrow r ^{\prime}= n ^{\frac{1}{3} r }$

$V =\frac{ kq }{ r } \propto \frac{ n }{ n ^{1 / 3}} \propto n ^{2 / 3} \propto 27^{2 / 3} \Rightarrow v ^{\prime}=9 V =9 \times 22=198$

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
    Figure shows three points $A$, $B$ and $C$ in a region of uniform electric field $\overrightarrow E $. The line $AB$ is perpendicular and $BC$ is parallel to the field lines. Then which of the following holds good. Where ${V_A} > {V_B}$ and ${V_C}$ represent the electric potential at points $A$, $B$ and $C$ respectively
    View Solution
  • 2
    In a parallel plate capacitor the separation between the plates is $3\,mm$ with air between them. Now a $1\,mm$ thick layer of a material of dielectric constant $2$ is introduced between the plates due to which the capacity increases. In order to bring its capacity to the original value the separation between the plates must be made......$mm$
    View Solution
  • 3
    An electric dipole when placed in a uniform electric field $E$ will have minimum potential energy, when the angle made by dipole moment with field $E$ is
    View Solution
  • 4
    Two identical positive charges are placed at $x =\, -a$ and $x = a$ . The correct variation of potential $V$ along the $x-$ axis is given by
    View Solution
  • 5
    Seven capacitors, each of the capacitance $2\,\mu F$, are to be connected in a configuration to obtain an effective capacitance of $\left( {\frac{6}{{13}}} \right)\,\mu F$. Which of the combinations, shown in figures below, will achieve the desired value ?
    View Solution
  • 6
    Two capacitors ${C_1} = 2\,\mu \,F$ and ${C_2}\, = \,6\,\mu \,F$ in series, are connected in parallel to a third capacitor ${C_3} = \,4\,\mu \,F$. This arrangement is then connected to a battery of $e.m.f.$ $=$ $2V$, as shown in the figure. How much energy is lost by the battery in charging the capacitors
    View Solution
  • 7
    On increasing the plate separation of a charged condenser, the energy
    View Solution
  • 8
    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
    View Solution
  • 9
    The plates of a capacitor are charged to a potential difference of $320 \, volts$ and are then connected across a resistor. The potential difference across the capacitor decays exponentially with time. After $1 $ second the potential difference between the plates of the capacitor is $240 \, volts$, then after $2$ and $3$ seconds the potential difference between the plates will be
    View Solution
  • 10
    The dielectric strength of air at $NTP$ is $3 \times {10^6}\,V/m$ then the maximum charge that can be given to a spherical conductor of radius $3\, m$ is
    View Solution