You Do Need power plug adapter while traveling from Palestine to Cocos (Keeling) Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Cocos (Keeling) Islands is I and in Palestine are C and H. This is how they look like.

Palestine

In Palestine, outlets of type C and H are in use.

Type C

Type H

Cocos (Keeling) Islands

In Cocos (Keeling) Islands, outlets of type I are in use.

Type I