00:01
We have a coaxial cable with an inner radius a of 0 .8 millimeters, which is equivalent to 0 .0008 meters.
00:16
And similarly, the outer radius, or at least the inside of the outer cylinder, is 3 millimeters, which is 0 .003 meters.
00:27
And now this is basically a concentric cylindrical capacitor, and the capacitance of such a setup is 2 pi epsilon.
00:39
Usually it's epsilon not, but this time it's just epsilon because we have a dielectric material.
00:46
And epsilon is just kappa times epsilon not, multiplied by l, and then divide by ln, b over a.
00:57
And now the capacitance is the charge over the voltage or the potential difference.
01:08
So now i can solve for the potential, which is going to be q times ln, b over a, over 2 pi epsilon l.
01:26
Now we have q over l, which is lambda, the linear charge density.
01:31
So this is lambda times lnb over a.
01:40
And now we have the expression for the potential, but we also know what the field is.
01:50
The field inside or between the two cylinders, or between the two radii of concentric cylinders, is going to be lambda over 2 pi epsilon r.
02:06
And now we're looking for, we know the dielectric strength, and that's going to happen at the inner radius of a, and now we have an expression for the field that looks very similar to the voltage...