MCQ
A parallel plate capacitor with plate are $A$ and seperation between the plates $d$, is charged by a constant current $i$, consider a plane surface of area $A/2$ parallel to the plates and drawn symmetrically between the plates, the displacement current through this area, will be.
  • A
    $i$
  • $\frac{i}{2}$
  • C
    $\frac{i}{4}$
  • D
    None of these

Answer

Correct option: B.
$\frac{i}{2}$
b
(b) Suppose the charge on the capacitor at time $t$ is $Q$, the electric field between the plates of the capacitor is $E = \frac{Q}{{{\varepsilon _0}A}}.$ The flux through the area considered is ${\phi _E} = \frac{Q}{{{\varepsilon _0}A}}.\frac{A}{2} = \frac{Q}{{2{\varepsilon _0}}}$
$\therefore$  The displacement current
${i_d} = {\varepsilon _0}\frac{{d{\phi _E}}}{{dt}} = {\varepsilon _0}\left( {\frac{1}{{2{\varepsilon _0}}}} \right)\frac{{dQ}}{{dt}} = \frac{i}{2}.$

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

A lift is moving downwards with an acceleration equal to acceleration due to gravity. A body of mass $m$ kept on the floor of the lift is pulled horizontally. If the coefficient of friction is $\,\mu $, then the frictional resistance offered by the body is
Identify the logic operation carried out by the given circuit :-
Match List $I$ with List $II$ :

List $I$ (Physical Quantity) List $II$ (Dimensional Formula)
$(A)$ Pressure gradient $(I)$ $\left[ M ^0 L ^2 T ^{-2}\right]$
$(B)$ Energy density $(II)$ $\left[ M ^1 L ^{-1} T ^{-2}\right]$
$(C)$ Electric Field $(III)$ $\left[ M ^1 L ^{-2} T ^{-2}\right]$
$(D)$ Latent heat $(IV)$ $\left[ M ^1 L ^1 T ^{-3} A ^{-1}\right]$

Choose the correct answer from the options given below:

Two long parallel copper wires carry currents of $5\,A$ each in opposite directions. If the wires are separated by a distance of $0.5\,m$, then the force between the two wires is
A wheel completes $2000$ revolutions to cover the $9.5\, km$. distance. then the diameter of the wheel is
$Assertion :$ At a given temperature the specific heat of a gas at constant pressure. is always greater than its specific heat at constant volume

$Reason :$ When a gas is heated at constant volume some extra heat is needed compared to that at constant pressure for doing work in expansion.

In the circuit shown, the cell has $emf = 10\,V$ and internal resistance $= 1\, \Omega$ :-
In the ladder network shown, current through the resistor $3\, \Omega$ is $0.25\,A$. The input voltage $'V'$ is equal to:- ........... $V$
Which of the following graphs shows the variation of electric field $E$ due to a hollow spherical conductor of radius $R$ as a function of distance $r$ from the centre of the sphere
A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is :