The US uses two standard electrical plug types: Plug Type A and Plug Type B. Both have two parallel pins for power, while the latter has an additional grounding pin for safety. But if you look closely ...

Metal prongs on a type-A electrical plug. - JACKREZNOR/Shutterstock Most gadgets and small appliances in U.S. homes have either a Type A or Type B electrical plug, perhaps with a cover to hide cords.

Add Yahoo as a preferred source to see more of our stories on Google. close up of Type A plug prongs - Gabriel Lopez/Shutterstock If you've ever stared at the holes in an electrical plug and wondered ...