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

Here is Why You Need An Adapter

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

Pakistan

In Pakistan, outlets of type C and D are in use.

Type C

Type D

Yemen

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

Type A

Type D

Type G