Norway runs on 230 V at 50 Hz, with sockets following Types C and F. At 230 V the supply matches what UK and European appliances expect, so no converter is needed.
The same socket system is used in Bosnia and Herzegovina, Andorra, Serbia and Russia, so one adapter covers all of them. Watch out when moving on: Malta, Ireland and the Isle of Man use a completely different system. 31 of the 50 destinations in Europe share the plug types of Norway.
Protective earth
Grounded and ungrounded sockets may occur
Norway has sockets with a protective earth (Type F) and without (Type C). A plug that fits mechanically does not guarantee earthing.