Q: You are given a passage. Using the information present in the passage, you need to classify it into one of the 10 topics: 0 - 'Society & Culture', 1 - 'Science & Mathematics', 2 - 'Health', 3 - 'Education & Reference', 4 - 'Computers & Internet', 5 - 'Sports', 6 - 'Business & Finance', 7 - 'Entertainment & Music', 8 - 'Family & Relationships', 9 - 'Politics & Government'.
Practical: As there are multiple very-incompatible voltages in use (110v, 220v), it's a good idea to not have the same plugs. Somebody will inevitably plug in the wrong device, and putting a 110v device on 220v can be pretty nasty. Dual voltage devices which are popular today (largely due to power semiconductors which make them inexpensive), didn't exist when plugs were designed!

Political: Many ex-colonies of Britain were trying to shake off British influence as far as possible, which probably was a factor in picking different system for power device standards, among others.
A:
1