Advertisements
Advertisements
प्रश्न
A parallel plate capacitor is being charged by a time varying current. Explain briefly how Ampere’s circuital law is generalized to incorporate the effect due to the displacement current ?
उत्तर
When a capacitor is connected to an alternating current, it offers a resistance `X_e (1/(omegac))`and allows the current to pass through.
As the current is moving from plate (1) to plate (2) there should be a magnetic field associated with this current as explained by Ampere circuital law, but as there can’t be movement of actual electrons from plate (2) to plate (1), there will be no physical current, and still there will be a magnetic field.
To solve this paradox Maxwell altered the form of Ampere’s law as followed.
Original form
`int_c vecE*vecdl =mu_0i +mu_0 in_0 (dphi)/(dt)`
`=mu_0 (i +i_D)`
`i_D = in_0 (dphi_(E))/(dt)`(Displacement current)
`phi_E` = Electric flux
By introducing displacement current, Maxwell argued that due to change in electric field associated with alternating voltage, there will be a time dependent electric flux. This flux will cause a displacement current and hence there will be a magnetic field.
APPEARS IN
संबंधित प्रश्न
What meaning would you give to the capacitance of a single conductor?
Net capacitance of three identical capacitors in series is 2 μF. What will be their net capacitance if connected in parallel?
When a dielectric slab is gradually inserted between the plates of an isolated parallel-plate capacitor, the energy of the system decreases. What can you conclude about the force on the slab exerted by the electric field?
A dielectric slab is inserted between the plates of an isolated capacitor. The force between the plates will
Define the dielectric constant of a medium. What is its S.I unit?
Two parallel uniformly charged infinite plane sheets, '1' and '2', have charge densities + `sigma and -2sigma `respectively. Give the magnitude and direction of the net electric field at a point.
(i) in between the two sheets and
(ii) outside near the sheet '1'.
In a parallel plate air capacitor the distance between plates is reduced to one-fourth and the space between them is filled with a dielectric medium of constant 2. If the initial capacity of the capacitor is 4μF then its new capacity is ______.
A free electron and a free proton are placed between two oppositely charged parallel plates. Both are closer to the positive plate than the negative plate.
Which of the following statements is true?
- The force on the proton is greater than the force on the electron.
- The potential energy of the proton is greater than that of the electron.
- The potential energy of the proton and the electron is the same.
When air replace by dielectric medium of constant K, the maximum force of attraction between two charges separate by a distance.
Two infinitely long parallel conducting plates having surface charge densities +σ cand -σ respectively are separated by a small distance. The medium between the plates is a vacuum. If ε0 is the dielectric permittivity of the vacuum, then the electric field in the region between the plates is ______.
