Question

How charges are accumulated on metallic plates of capacitor

Answer 1

+|- +|-
+|- +|-
(positive end of battery) +|- +|- (negative end of battery)
+|- +|-
+|- +|-

Whenever a capacitor is connected to battery, the plate of the capacitor connected to positive end of battery accumulates positive charge on the outside & then the inner part of that same plate get negatively charged due to induction, after that since the inner part of 1st plate have negative charge so it will induce positive charge on the inner part of the 2nd plate & at last the outer part of 2nd plate again get induced with negative charge because of the accumulated positive charge on the inner side of 2nd plate.

I think explanation is some what messy, so sorry for that, hope you will find it helpful!