# How is the formula for the capacitance of a parallel plate capacitor derived?

I have seen in I.E. Irodov that if the permittivity is given as $\epsilon$ then we can find the capacitance as $$C = \frac{\epsilon A}{d}$$ but I wonder whether it is dimensionally correct or not and how it is obtained?

• Hi @satyatch. If you use dollar marks $\$$around your text, you can make good-looking math and formulas. See here physics.stackexchange.com/editing-help#latex. If you could edit your question to be more clear, it would help me to understand it better. Jun 28, 2015 at 15:09 • Is this the equation you are refering to? en.wikipedia.org/wiki/Capacitance#Capacitors$$C=\epsilon_r\epsilon_0\frac{A}{d}$\$ Jun 28, 2015 at 15:11
• @steeven Yes I am asking that but what is the proof of it. Jun 28, 2015 at 15:35
• Do you know about gaussian surfaces? Jun 28, 2015 at 20:36
• – Rol
Jul 5, 2015 at 13:51