In a parallel plate capacitor with air between the plates, each has an area `8xx10^(-3)m^(2)` and distance between the plates is 2 mm. Calculate the capacitance of the capacitor. If this capacitor is connected to a 50 V supply, what is the charge on each plate of the capacitor? (Absolute permittivity of free space `=8.85xx10^(-12)Fm^(-1))`

Explanation

Given `A=8xx10^(-3) m^2 , d=2xx10^(-3)`m
`C_"air"`=?
V=50 V , Q=?
`e_0=8.85xx10^(-2) Fm^(-1)`

WKT electrical capacitance of an air capacitor
`C=(epsilon_0A)/d`
i.e., `C=(8.85xx10^(-2) xx8xx10^(-3))/(2xx10^(-3))`
i.e., `C=35.416xx10^(-2)` (farad)
Also,
WKT Q=charge an the capacitor =CV
i.e., `Q=35.416xx10^(-12)xx50`
`=1770.8xx10^(-12)` C
`Q=1.771xx10^(-9)` C (Coulomb )