The Norwegian Museum of Science and Technology is one of Oslo's best family museums, with hands-on exhibits on industry, medicine, transport, energy, and communication. It also incorporates the Norwegian Telecommunications Museum, so old phones, switchboards, and broadcasting equipment sit beside broader science displays.
The museum is north of the centre, but it rewards the trip if you are travelling with children or like practical, touchable museums. Allow more time than you think: the interactive sections are the point, not a quick walk-through.