MCQ
A $16\  \Omega$ wire is bend to form a square loop. A $9 \mathrm{~V}$ battery with internal resistance $1\  \Omega$ is connected across one of its sides. If a $4\  \mu \mathrm{F}$ capacitor is connected across one of its diagonals, the energy stored by the capacitor will be $\frac{x}{2} \ \mu \mathrm{J}$. where $x=$________.
  • A
    $52$
  • B
    $42$
  • $81$
  • D
    $12$

Answer

Correct option: C.
$81$
c
$ I=\frac{V}{R_{e q}} I=\frac{V}{R_{e q}}=\frac{9}{1+\frac{12 \times 4}{12+4}}=\frac{9}{4} $

$ I_1=\frac{9}{4} \times \frac{4}{16}=\frac{9}{16} $

$ V_A-V_B=I_1 \times 8=\frac{9}{16} \times 8=\frac{9}{2} V $

$ \therefore U=\frac{1}{2} \times 4 \times \frac{81}{4} \mu \mathrm{J} $

$ \therefore U=\frac{81}{2} \mu \mathrm{J} $

$ \therefore \mathrm{X}=81$

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

The magnetic field at the centre of a circular current carrying-conductor of radius $r$ is $B_c$. The magnetic field on its axis at a distance $r$ from the centre is $B_a$. The value of $B_c$ : $B_a$ will be
Two thin conducting shells of radii $R$ and $3R$ are shown in the figure. The outer shell carries a charge $+ Q$ and the inner shell is neutral. The inner shell is earthed with the help of a switch $S$.
The number of turns in primary and secondary coils of a transformer are 100 and 300 respectively. If in- put power is 60 W, then output power will be:
Four charges $2C, -3C, -4C$ and $5C$ respectively are placed at all the corners of a square. Which of the following statements is true for the point of intersection of the diagonals ?
Two coaxial solenoids are made by winding thin insulated wire over a pipe of cross-sectional area $A = 10\ cm^2$ and length$= 20\ cm$. If one of the solenoid has $300$ turns and the other $400$ turns, their mutual inductance is

$\mu_{0}=4 \pi \times 10^{-7} \;TmA ^{-1}$

Assertion : Goggles have zero power.

Reason : Radius of curvature of both sides of lens is same.

Space between two concentric conducting spheres of radii $a$ and $b (b > a)$ is filled with $a$ medium of resistivity $\rho $. The resistance between the two spheres will be
A charge particle is moving in a uniform magnetic field $(2 \hat{i}+3 \hat{j}) T$. If it has an acceleration of $(\alpha \hat{i}-4 \hat{j}) m / s ^{2}$, then the value of $\alpha$ will be.
For the given reaction, the particle $X$ is $_6{C^{11}}{ \to _5}{B^{11}} + {\beta ^ + } + X$

 

In the figure, shown the magnetic induction at the centre of there arc due to the current in portion AB will be