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Science and Nature
Physics Girl

Why outlets spark when unplugging - EMF & Inductors

Join host Dianna Cowern as she puts her MIT physics degree to the test. With experiments, demonstrations, and cool new discoveries, Physics Girl sheds new light on the fun, adventurous side of physical science.

Why outlets spark when unplugging - EMF & Inductors

Season 2 Episode 20 | 6m 30s | CC

When we cut the electricity to an inductor, we get a sudden intense spark across the switch. This is known as inductive kickback or a back EMF and is produced because of Faraday’s Law of Induction. Not mean to be tried at home! The inductor doesn’t want to change its current, so the change in magnetic field creates an EMF resulting in a high voltage across the switch. #PHYSICS

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