You Do Need power plug adapter while traveling from Equatorial Guinea to Yemen.

Here is Why You Need An Adapter

The outlet and plug type used in Yemen are A, D and G and in Equatorial Guinea are C and E. This is how they look like.

Equatorial Guinea

In Equatorial Guinea, outlets of type C and E are in use.

Type C

Type E

Yemen

In Yemen, outlets of type A, D and G are in use.

Type A

Type D

Type G