Question

three identical charged capacitors each of capacitance 5 uf are connected as shown in figure the potential difference across capacitor 3 a long time after the switches K1 and K2 are closed is ​

Answer 1

after long time, charge remains conserved on the individual plates.

initially, charge on each plate, Q = 100uC

so, total charge on plates , Qnet = 3Q = 300uC

see diagram,

$Q_1+Q_3=Q+Q=2Q$.....(1)

$-Q_1+Q_2=-Q+Q=0\implies Q_1=Q_2$.....(2)

and net charge after long time, Qnet =$Q_1+Q_2+Q_3=3Q$....(3) [ charge remains conserved]

from equations (1), (2) and (3),

$Q_1=Q,Q_2=Q$ And $Q_3=Q$

so, potential difference across capacitor 3 , V = Q/C = 100uC/5uF = 20volts

hence, answer is 20V.

Answer 2

Answer:

in the wire the charge is zero thus final charge is zero

∆v=o