Question

15. In the given circuit, the electric potential of P will be
(1) 5 V
(2) 6 V
(3) 8 V
(4) 9V

Answer 1

Explanation:

C1 =3, C2= 1 &C3 = 2

C12( series) = (3 X1)/ 4 = 3/4 uF

C123 ( series) = (3/4 x 2)/ ( 3/4 + 2) =( 3/2) / 11/4

= 12/ 22 = 6 /11 uF

Q = C V = 6/11 x 11= 6uC

( 11 - P) across 3uF

( P - 0)across 2/3 uF

( 11 - P) + (P - 0) = 11

pd across 3uF is

Q = C (11 - P)

6 = 3 (11 - P)

3P = 33 -6 = 27

P = 9V

ans is option 4.