Question

Consider the circuit shown in figure. If the charge on 4mF capacitor is 12 mC, then charge on 6mF capacitor will be –

• A. 9 mC
• B. 18 mC
• C. 36 mC
• D. 54 mC

Answer 1

Answer: (D)

54 mC

Answer 2

Vat 4mF = = $\frac { 12 } { 4 }$ = 3V

\ Vat 6mF (Resultant of 2mF & 4mF) = 3V

Charge on this 6mF = CV = 6 × 3 = 18 mcf

C_eq. of 6mF & 3mF = $\frac { 6 \times 3 } { 6 + 3 }$ = 2mF and this also has 18 mcb charge. =

Q_6mF = $\frac { 6 } { 2 }$ × Q_2mF = 3 × 18 = 54mC