Calculating Magnetic Field Strength for Parallel-Plate Capacitor

[spacemanrussell]

Homework Statement

A 10-cm-diameter parallel-plate capacitor has a 1.0 mm spacing. The electric field between the plates is increasing at the rate 1*10^6V/m/s.

What is the magnetic field strength 3.0 cm from the axis?

Homework Equations

B= uo/(2*pi) *r/R^2*(Chang in Q/ change in time)

The Attempt at a Solution

I keep getting 2.4

 

[kevin7913]

I think you need to change the unites for the increase rate to C/s.
anyone knows how?

 

[spacemanrussell]

Oh good thinking- I probably need to accound for the charge of an electron.

 

[kevin7913]

I got the answer from masteringphysics.com 1.67*10^-13 T.
Now what is the magnetic field strength 7cm from the axis?