Question
You are given a 2μF parallel plate capacitor. How would you establish an instantaneous displacement current of 1mA in the space between its plates?
✓
Answer
The capacitance of capacitor $\text{C}=2\mu\text{F}$,
Displacement current Id = 1mA
Charge in capacitor, q = CV
$\text{I}_\text{d}\text{dt}=\text{Cdv}\ \ \big[\because\ \text{q}=\text{it}\big]$
or $\text{I}_\text{d}=\text{C}\frac{\text{dV}}{\text{dt}}$
$1\times10^{-3}=2\times10^{-6}\times\frac{\text{dV}}{\text{dt}}$
or $\frac{\text{dV}}{\text{dt}}=\frac{1}{2}\times10^{3}=500\text{V/s}$
Hence by applying a varying potential difference of 500V/s, we would produce a displacement current of desired value.
Displacement current Id = 1mA
Charge in capacitor, q = CV
$\text{I}_\text{d}\text{dt}=\text{Cdv}\ \ \big[\because\ \text{q}=\text{it}\big]$
or $\text{I}_\text{d}=\text{C}\frac{\text{dV}}{\text{dt}}$
$1\times10^{-3}=2\times10^{-6}\times\frac{\text{dV}}{\text{dt}}$
or $\frac{\text{dV}}{\text{dt}}=\frac{1}{2}\times10^{3}=500\text{V/s}$
Hence by applying a varying potential difference of 500V/s, we would produce a displacement current of desired value.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Draw a schematic arrangement of the Geiger - Marsden experiment. How did the scattering of $\alpha-$ particles by a thin foil of gold provide an important way to determine an upper limit on the size of the nucleus? Explain briefly.
→The density of water at 0°C is 0.998g cm-3 and at 4°C is 1000g cm-3.Calculate the average coefficient of volume expansion of water in the temperature range 0 to 4°C.
We have valence electrons and conduction electrons in a semiconductor. Do we also have 'valence holes' and 'conduction holes'?
Iron emits $\text{K}_\alpha$ X-ray of energy 6.4keV and calcium emits $\text{K}_\alpha$ X-rays of energy 3.69 keV. Calculate the times taken by an iron $\text{K}_\alpha$ photon to cross through a distance of 3km.
→A ball is dropped from a balloon going up at a speed of 7m/s. If the balloon was at a height 60m at the time of dropping the ball, how long will the ball take in reaching the ground?
- Define the term intensity of radiation' in photon picture.
- Plot a graph showing the variation of photo current vs collector potential for three different intensities I1 > I2 >I3, two of which (I1 and I2) have the same frequency v and the third has frequency v1 > v.
- Explain the nature of the curves on the basis of Einstein's equation.
The given graph shows a plot of magnetic flux $(\phi)$ and the electric current (I) flowing through two inductors P and Q. Which of the two inductors has smaller value of self-inductance?
→
A wheel rotating with uniform angular acceleration covers 50 revolutions in the first five seconds after the start. Find the angular acceleration and the angular velocity at the end of five seconds.
Area of a parallel plate capacitor is A and distance between them is $d$. It is charged with a constant current of I. An element of area $\frac{A}{2}$ is kept in the middle of the plates, parallel to the plates. What is the current flowing through this area?
→Consider a non-conducting ring of radius r and mass m that has a total charge q distributed uniformly on it. The ring is rotated about its axis with an angular speed $\omega.$
→- Find the equivalent electric current in the ring.
- Find the magnetic moment $\mu$ of the ring.
- Show that $\mu=\frac{\text{q}}{2\text{m}}\text{l}$ where l is the angular momentum of the ring about its axis of rotation.