Capacitor Networks

Capacitors For each of these three circuits calculate the total capacitance; and draw the equivalent circuit. Circuit 3 10 pF R R 6.7 pF 10 pF 20 pF R

Capacitors Which of the capacitors (8, 128, or 32 pF) stores the most electric charge (Q) in each of these circuit diagrams? You must explain your answer with or without values of Q 128 pF 8 pF 32 pF 12 V 8 pF 32 pF 128 pF 12 V circuit 2 circuit 1 R 128 pF 32 pF 8 pF 12 V circuit 3 R R

Capacitors Which of the capacitors (8, 128, or 32 pF) stores the most electric charge (Q) in each of these circuit diagrams? You must explain your answer with or without values of Q R 8 pF 32 pF 128 pF 12 V circuit 1 Q8 = CV Q8 = 8 x 10-12 x 12 = 96 x 10-12 C Q128= CV Q128 = 128 x 10-12 x 12 = 1536 x 10-12 C Q32 = CV Q32 = 32 x 10-12 x 12 = 384 x 10-12 C 128 pF For a fixed voltage. The greater the capacitance the greater the amount of charge can be stored.

QT = CTVT QT = 6 x 10-12 x 12 QT = 72 x 10-12 C V32pF = 2.3 V Capacitors Which of the capacitors (8, 128, or 32 pF) stores the most electric charge (Q) in each of these circuit diagrams? You must explain your answer with or without values of Q The total capacitance CT = 6 pF 128 pF 8 pF 32 pF 12 V circuit 2 QT = CTVT QT = 6 x 10-12 x 12 QT = 72 x 10-12 C R All the same Capacitors connected in series store the same quantity of charge no matter what their values are. The quantity of charge each capacitor can store is determined by the total capacitance (6 mF) which is always less then the lowest value capacitor (8 mF). The quantity of charge each capacitor stores is 72 x 10-12 C. V32pF = 2.3 V V128pF = 0.56 V

8 pF capacitor stores the most charge. Which of the capacitors (8, 128, or 32 pF) stores the most electric charge (Q) in each of these circuit diagrams? You must explain your answer with or without values of Q 128 pF 32 pF 8 pF 12 V circuit 3 8 pF 160 pF R 12 V R 8 pF capacitor stores the most charge. The equivalent capacitance of the parallel section is 160 pF. Capacitors connected in series store the same quantity of charge no matter what their values are. The quantity of charge stored is determined by the total capacitance (7.6 pF) which is always limited by the lowest value capacitor (8 pF). The quantity of charge on the 8 pF is 91 x 10-12 C and this is shared between the parallel pair. (Detailed calculations follow)

QT = CTVT QT = 7.6 x 10-12 x 12 QT = 91 x 10-12 C CT = C1 + C2 Capacitors detailed working for circuit 3. 128 pF 32 pF 8 pF 12 V R circuit 3 8 pF 160 pF 7.6 pF QT = CTVT QT = 7.6 x 10-12 x 12 QT = 91 x 10-12 C CT = C1 + C2 CT = 128 + 32 CT = 160 pF

Capacitors detailed working for circuit 3. QT = 91 x 10-12 C 128 pF 32 pF 8 pF 12 V 7.6 pF 160 pF 8 pF QT = 91 x 10-12 C Q8 = 91 x 10-12 C Q32 = C32V Q32 = 32 x 10-12 x 0.6 Q32 = 19 x 10-12 C Q128 = (91 – 19) x 10-12 C Q128 = 72 x 10-12 C