This video tutorial is in the electronics category and it is going to show you how to lock and prevent an extension cord from unplugging. When you plug in an extension cord, there is always a chance it getting undone accidentally. There is also the possibility of the pins getting slightly bent. So, you need to lock the extension cord. There is a real simple way to do this. All you got to do is just tie a simple knot before plugging in the cord. Now even if someone pulls at both the ends of the cord, it will still not get unplugged.