- #1
Opus_723
- 178
- 3
Homework Statement
Show that the transformation
[itex]w = e^{z} + z[/itex]
maps the infinite lines [itex]y = \pm\pi[/itex] into semi-infinite lines [itex]u \leq u_{0}, v = \pm\pi[/itex]. This is equivalent to transforming an infinite or edgeless parallel-plate capacitor (z-plane) into a parallel plate capacitor (w-plane). Sketch the equipotentials in the w-plane near the edge of the capacitor plates.
Find the electric field at the plane midway between the two plates (at v = 0) as a function of u.
Homework Equations
I found parametric equations for the equipotentials:
[itex] u = x + cos(\frac{\pi*V}{V_{0}})*e^{x}[/itex]
[itex] v = \frac{\pi*V}{V_{0}} + sin(\frac{\pi*V}{V_{0}})*e^{x}[/itex]
The Attempt at a Solution
But I don't know how to find the electric field as a function of u along the axis. If I had an expression for V I would simply take the gradient, but buried as it is inside these parametric equations, I don't know how to get at it. I managed to elimnate x:
[itex] x = ln(\frac{v-\pi*V/V_{0}}{sin(\frac{\pi*V}{V_{0}})})[/itex]
But I'm not sure how to proceed from there.