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

Here is Why You Need An Adapter

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

Brazil

In Brazil, outlets of type C and N are in use.

Type C

Type N

Yemen

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

Type A

Type D

Type G