question_answer 6)

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?  

Answer:

(a) Here,                                 i.e.                                 or Ceq = 3 × 10?12 F = 3 pF. (b) Here V1 + V2 + V3 = 120                 i.e.                                 i.e.                 i.e.                 or q = 360 × 10?12 F                            P.F. across a capacitor                                 Short cut: Since three equal capacitors are across 120 V, so p.d. across each capacitor.