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Electronic Principles Home Work

Andrew Younger

Jan 11, 2017
2
Joined
Jan 11, 2017
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2
Hi I am struggling with a question at the moment and wonder if someone can help me get my head around it.

Calculate C for a mica capacitor with:
- Relative permittivity: 8
- thickness of: 0.02cm
- Plates of 6cm2

I have got for the equation:
C= A/d x ER E0

So:
C = 6 x 10*4 / 0.02 x 10*-2 x 8 x 8.85 x 10*-12 = The answer I am getting is 2.124 x 10*-14

Where am I going wrong?? Thanks for any help :)
 

duke37

Jan 9, 2011
5,364
Joined
Jan 9, 2011
Messages
5,364
It would be better to use SI units. Why make things complcated with sub units?
It would be better to use brackets to define your equation properly or rearrange to not need them.

Wikipedia gives E0 as 8.85E-12 Farads/m
Area 6cm2 = 6E-4m^2 Check this, the area could be 6cm by 6cm i.e. 36cm^2
Thickness = 0.02cm = 2E-4 m
C = A* Er*E0/d =212pF

Please check, my abacus and its driver are quite old.
 

Arouse1973

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
I did think that about the units but I guess they want them to spot that and try and work it out. Your wooden beads are working correctly Trevor. :)
Adam
 
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