Three capacitors each of capacitance 9 pF are connected in series.

(a) What is the total capacitance of the combination?


(b) What is the potential difference across each capacitor if the combination is connected to a 120 V supply?

Given, C1 = C2 = C3 = 9 pF = 9 x 10-12 F

V = 120 volt



(a) Total capacitance of the series combination is given by



⇒


⇒



Cnet = 3 x 10-12 F = 3 pico-Farad.


(b) Let q be the charge on each capacitor.


Sum of the potential difference across the plates of the three capacitors must be equal to 120 V


⇒ V1 + V2 + V3 = Vnet


⇒ (∵ Vnet = 120 V)


⇒


⇒


⇒ q = 360 x 10-12 C


Therefore, potential difference across a capacitor



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