You Do Need power plug adapter while traveling from Micronesia to United Kingdom (UK).

Here is Why You Need An Adapter

The outlet and plug type used in United Kingdom (UK) is G and in Micronesia are A and B. This is how they look like.

Micronesia

In Micronesia, outlets of type A and B are in use.

Type A

Type B

United Kingdom (UK)

In United Kingdom (UK), outlets of type G are in use.

Type G