File:VFPt capacitor-square-plate.svg
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Original file (SVG file, nominally 800 × 600 pixels, file size: 27 KB)
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Summary
| Description |
English: Accurately computed electric field of simple parallel plate capacitor. The capacitor consists of two square plates with plate size a and distance d=a/3. The field is accurately computed for a uniform charge distribution on each plate, but therefore the potential on each plate is not exactly constant. |
| Date | |
| Source | Own work |
| Author | Geek3 |
| Other versions |
Slightly different field configurations:
|
| SVG development |  This plot was created with VectorFieldPlot. |
| Source code | Python code# paste this code at the end of VectorFieldPlot 2.0
doc = FieldplotDocument('VFPt_capacitor-square-plate', width=800, height=600, commons=True)
l = 4.5
d = 1.5
plates = [{'x0':-l/2., 'y0':d/2., 'x1':l/2., 'y1':d/2., 'Lz':l, 'Q':1.},
{'x0':-l/2., 'y0':-d/2., 'x1':l/2., 'y1':-d/2., 'Lz':l, 'Q':-1.}]
field = Field([['charged_rect', plates[0]], ['charged_rect', plates[1]]])
def startpath(t):
# take an oval with stright lines and half-cirles around one plate
tt = (t%1) * (2 * l + pi * d)
if tt <= l*0.5:
return sc.array([tt, d])
elif tt <= l*0.5 + pi/2.*d:
phi = (tt - l*0.5) / (d/2.)
return sc.array([l*0.5 + d*0.5*sin(phi), d*0.5 + d*0.5*cos(phi)])
elif tt <= l*1.5 + pi/2.*d:
return sc.array([l - (tt - pi/2.*d), 0.])
elif tt <= l*1.5 + pi*d:
phi = (tt - l*1.5) / (d/2.)
return sc.array([-l*0.5 + d*0.5*sin(phi), d*0.5 + d*0.5*cos(phi)])
else:
return sc.array([tt - (l*2. + pi*d), d])
nlines = 22
p0list = Startpath(field, startpath).npoints(nlines)
# plot field lines
for p0 in p0list:
line = FieldLine(field, p0, directions='both')
doc.draw_line(line, arrows_style={'dist':2, 'min_arrows':1})
# plot capacitor plates
D = 0.055
lw = 0.01
nsign = nlines
plus = 'M 0,-0.02 v 0.04 M -0.02,0 h 0.04'
minus = 'M -0.02,0 h 0.04'
for p in plates:
M = 0.5 * (sc.array([p['x0'], p['y0']]) + sc.array([p['x1'], p['y1']]))
R = sc.array([p['x1'], p['y1']]) - M
a = atan2(R[1], R[0])
if p['Q'] > 0:
col = '#e22'
sign = plus
else:
col = '#45e'
sign = minus
transform = 'translate({:.6g},{:.6g})'.format(M[0], M[1])
transform += ' rotate({:.6g})'.format(degrees(a))
doc.draw_object('rect', {'x':-vabs(R)-lw/2., 'width':2*vabs(R)+lw,
'y':-D, 'height':2*D,
'style':'fill:{:s}; stroke:#000; stroke-width:{:.6g}'.format(col, lw),
'transform':transform})
for i in range(nsign):
pos = M + R * (2 * (i + 0.5) / nsign - 1)
doc.draw_object('path', {'d':sign,
'transform':'translate({:.6g},{:.6g})'.format(*pos),
'style':'fill:none; stroke:#000; stroke-width:{:.6g}; '.format(2*lw) +
'stroke-linecap:square'})
doc.write()
|
Licensing
I, the copyright holder of this work, hereby publish it under the following license:
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 21:50, 7 September 2019 | | 800 × 600 (27 KB) | Geek3 | User created page with UploadWizard |
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