Capacitance is ability of a conductor to store electric charge between its plates.It is defined as the ratio of electric charge that stored in the capacitor and the potential difference between the plates of the capacitor. Capacitance is represented by C.
Thus, C = Q/V
Where, Q = Charge stored in capacitor
And V = Potential difference
S.I unit of capacitance is “Coulomb/Volt” or “Farad”(F).
Farad is a very large unit therefore in general we are using small units
Micro farad (uF) , 1 uF = 10^-6 F
Pico farad (uuF), 1 uuF = 10^-12 F
Example : Determine the capacitance of the capacitor if 10 coulombs charge is flowing through a 4 V battery.
Charge, Q = 10 C and
Voltage applied, V = 4 V
Now, we can use the formula for capacitance,
C = Q/V = 10/ 4 = 2.5 F
Example : Calculate the capacitance of a conductor if voltage across the capacitor is 0.658 V and the charge125 µµC flowing through it.
Charge, Q = 125 µµC and
Voltage, V = 0.658 V
Using the equation of capacitance,
C = Q/V = 125 /0.658 = 190 µµF.