How Does Charging a Capacitor Affect the Induced Magnetic Field?

[Sportsman4920]

Homework Statement

A 1400 nF capacitor with circular parallel plates 1.0 cm in diameter is accumulating charge at the rate of 25.0 mC/s at some instant in time. What will be the magnitude of the induced magnetic field 9.0 cm radially outward from the center of the plates?
T
What will be the magnitude of the field after the capacitor is fully charged?
T

Homework Equations

Obviously I'm a little confused, but I believe the general equation is B=mevE where B is magnetic field, e is c^2/Nxm^2, m is Nxs^2/C^2...on second, thought, I'm very confused.
another possibility is B=(mu) initial x I/ 2 pi r

The Attempt at a Solution

1400x25=35000x(1/9)=3888.89T

 

[marcusl]

Well some of your comments are on the right track. First you need to calculate the current, given the charge per second. Then use that current in your secon equation (often called the law of Biot and Savart).

However, don't forget to look at the units! You can't just plug in 25 without making use of its units milli-Coulomb.