Ampere/Maxwell law capacitor problem

In summary, a 0.200-A current is charging a capacitor with circular plates 10.0 cm in radius and a plate separation of 4.00 mm. The time rate of increase of electric field between the plates can be found using the Ampere-Maxwell law. However, finding the magnetic field between the plates 5.00 cm from the center is causing difficulty. The Ampere-Maxwell law tells us that the magnetic field is created by a time-varying electric field and a conduction current, but since a capacitor is being considered, the latter can be disregarded. To proceed with the problem, a cylinder can be constructed between the plates and the area, A, can represent its surface area.
  • #1
mcshadypl
4
0

Homework Statement


A 0.200-A current is charging a capacitor that has circular plates 10.0 cm in radius. If the plate separation is 4.00 mm, (a) what is the time rate of increase of electric field between the plates? (b) What is the magnetic field between the plates 5.00 cm from the center?


Homework Equations


Ampere-Maxwell law:
integral(B*ds) = u0I + e0u0*d(fluxE)/dt


The Attempt at a Solution


I have found the solution to part A, but B is what is causing me trouble. I have really no clue how to go about finding the magnetic field.
 
Physics news on Phys.org
  • #2
What does the Ampere-Maxwell law tell you? What do each of the terms represent?
 
  • #3
Well, it tells us what the magnetic field is that is created by a time-varying electric field as well as a conduction current. Since a capacitor is being considered, the latter part can be disregarded.

So I'm thinking that a cylinder can be constructed between the capacitors and we will assume that EA= u0e0*d(fluxE)/dt
I suppose that area, A, can represent the surface area of this cylinder such that A= pi(0.05m)2*(0.004m). So we want to find the magnetic field, which should be the "B" term of the integral portion of the equation. At this point I don't know how to proceed with the problem.
 

What is Ampere's law?

Ampere's law is one of the fundamental equations in electromagnetism, describing the relationship between electric currents and magnetic fields. It states that the magnetic field created by a closed loop of electric current is proportional to the magnitude of the current and the length of the loop.

What is Maxwell's law?

Maxwell's law, also known as the displacement current law, is a modification of Ampere's law that states that a changing electric field can create a magnetic field, just as a changing magnetic field can create an electric field. This law is essential for understanding electromagnetic waves and the behavior of capacitors.

What is a capacitor?

A capacitor is a device that stores electrical energy by storing opposite charges on two conductive plates separated by an insulating material. It is commonly used in electronic circuits to regulate the flow of electricity and can also be found in many other devices such as cameras, flashlights, and power supplies.

How does Ampere's law apply to capacitors?

Ampere's law can be used to calculate the magnetic field created by the current flowing through the conductive plates of a capacitor. This magnetic field plays a crucial role in the behavior of capacitors, as it affects how quickly they can charge and discharge.

How can I solve problems involving Ampere/Maxwell law and capacitors?

To solve problems involving Ampere/Maxwell law and capacitors, you will need to use various equations and principles from electromagnetism, such as Ampere's law, Maxwell's law, and the equations for calculating electric and magnetic fields. It is also helpful to have a good understanding of the behavior of capacitors and how they interact with electric and magnetic fields.

Similar threads

  • Introductory Physics Homework Help
Replies
18
Views
1K
Replies
4
Views
344
  • Introductory Physics Homework Help
Replies
11
Views
376
  • Introductory Physics Homework Help
Replies
26
Views
554
  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
175
  • Introductory Physics Homework Help
Replies
21
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
1K
Back
Top