You Do Need power plug adapter while traveling from Ethiopia 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 Ethiopia are C, F and G. This is how they look like.

Ethiopia

In Ethiopia, outlets of type C, F and G are in use.

Type C

Type F

Type G

United Kingdom (UK)

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

Type G