A capacitance of $2\ μF$ is required in an electrical circuit across a potential difference of $1.0\ kV$. A large number of $1\ μF$ capacitors are available which can withstand a potential difference of not more than $300\ V$. The minimum number of capacitors required to achieve this is
JEE MAIN 2017, Medium
Download our app for free and get startedPlay store
To get a capacitance of $2\, \mu \mathrm{F}$ arrangement of capacitors of capacitance $1\, \mu \mathrm{F}$ as shown in figure $8$ capacitors of $1\, \mu \mathrm{F}$ in parallel with four such branches in series i.e., $32$ such capacitors are required.

$\frac{1}{C_{e q}}=\frac{1}{8}+\frac{1}{8}+\frac{1}{8}+\frac{1}{8} \quad \therefore C_{e q}=2\, \mu F$

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
    In the circuit shown, $q_2$ and $q_3$ are respectively (Initially all capacitors are uncharged)
    View Solution
  • 2
    Two identical charged spheres are suspended by string of equal lengths. The string make an angle of $37^{\circ}$ with each other. When suspended in a liquid of density $0.7 \mathrm{~g} / \mathrm{cm}^3$, the angle remains same. If density of material of the sphere is $1.4 \mathrm{~g} / \mathrm{cm}^3$, the dielectric constant of the liquid is_____$\left(\tan 37^{\circ}=\frac{3}{4}\right)$.
    View Solution
  • 3
    The equivalent capacitance between $A$ and $B$ in the figure is $1\,\mu F$. Then the value of capacitance $C$ is.....$\mu F$
    View Solution
  • 4
    Two identical capacitors have same capacitance $C$. One of them is charged to the potential $\mathrm{V}$ and other to the potential $2 \mathrm{~V}$. The negative ends of both are connected together. When the positive ends are also joined together, the decrease in energy of the combined system is :
    View Solution
  • 5
    A sphere of radius $1\,cm$ has potential of $8000\,V$, then energy density near its surface will be
    View Solution
  • 6
    The variation of potential with distance $x$ from a fixed point is as shown in figure. The electric field at $x =13\,m$ is......$volt/meter$
    View Solution
  • 7
    The combined capacity of the parallel combination of two capacitors is four times their combined capacity when connected in series. This means that
    View Solution
  • 8
    A parallel plate capacitor has a dielectric slab of dielectric constant $K$ between its plates that covers $1 / 3$ of the area of its plates, as shown in the figure. The total capacitance of the capacitor is $C$ while that of the portion with dielectric in between is $C _1$. When the capacitor is charged, the plate area covered by the dielectric gets charge $Q_1$ and the rest of the area gets charge $Q_2$. Choose the correct option/options, igonoring edge effects.

    $(A)$ $\frac{E_1}{E_2}=1$ $(B)$ $\frac{E_1}{E_2}=\frac{1}{K}$ $(C)$ $\frac{Q_1}{Q_2}=\frac{3}{K}$ $(D)$ $\frac{ C }{ C _1}=\frac{2+ K }{ K }$

    View Solution
  • 9
    A spherical metal shell $A$ of radius $R_A$ and a solid metal sphere $B$ of radius $R_B\left( < R_A\right)$ are kept far apart and each is given charge ' $+Q$ '. Now they are connected by a thin metal wire. Then

    $(A)$ $E_A^{\text {lnside }}=0$

    $(B)$ $Q_A > Q_B$

    $(C)$ $\frac{\sigma_A}{\sigma_B}=\frac{R_B}{R_A}$

    $(D)$ $E_A^{\text {on sulface }} < E_B^{\text {on uurface }}$

    View Solution
  • 10
    A particle of mass $m$ and charge $q$ is placed at rest in a uniform electric field $E$ and then released. The kinetic energy attained by the particle after moving a distance $y$ is
    View Solution