MCQ
A parallel plate capacitor has a uniform electric field $E$ in the space between the plates. If the distance between the plates is $d$ and area of each plate is $A,$ the energy stored in the capacitor is 
  • A
    ${\varepsilon _0}EAd$
  • B
    $\;\frac{1}{2}{\varepsilon _0}\frac{{{E^2}}}{{Ad}}$
  • $\;\frac{1}{2}\;{\varepsilon _0}{E^2}Ad$
  • D
    $\;{\varepsilon _0}\frac{{{E^2}}}{{Ad}}$

Answer

Correct option: C.
$\;\frac{1}{2}\;{\varepsilon _0}{E^2}Ad$
c
Potential difference the between plates

$V=Ed$

Parallel Plate Capacitor -

$C=\frac{\varepsilon_0A}{d}$

Energy

$U=\frac{1}{2}CV^2$

$U=\frac{1}{2}\;{\varepsilon _0}{E^2}Ad$

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

Gauss's law in dielectric medium:
An illuminated object and a screen are placed $90\, cm$ apart. What is the focal length of  the lens required to produce an image on the screen, twice the size of object ?.......$cm$
$A$ converging lens of focal length $20\, cm$ and diameter $5\, cm$ is cut along the line $AB$. The part of the lens shown shaded in the diagram is now used to form an image of a point $P$ placed $30\,cm$ away from it on the line $XY$. Which is perpendicular to the plane of the lens. The image of $P$ will be formed.
A $50 \,mH$ coil carries a current of $2$ ampere. The energy stored in joules is
The angular spread of central maximum, in the diffraction pattern, does not depend on ______.
For transistor action, which of the following statements is correct$?$
The electric potential at a point $(x, y, z)$ is given by $V=-x^2y-xz^3 +4 $. The electric field at that point is  
A bar magnet has coercivity $4 \times {10^3}\,A{m^{ - 1}}.$ It is desired to demagnetise it by inserting it inside a solenoid $12\, cm$ long and having $60$ $turns$. The current that should be sent through the solenoid is....$A$
A uniform conducting wire ABC has a mass of 10g. A current of 2A flows through it. The wire is kept in a uniform magnetic field B = 2T. The acceleration of the wire will be
A particle of mass $m$ and charge $q$ enters a region of magnetic field (as shown) with speed $v$. There is a region in which the magnetic field is absent, as shown. The particle after entering the region collides elas tically with a rigid wall. Time after which the velocity of particle becomes anti parallel to its initial velocity is