Episode

BrainStuff

HowStuffWorks

Science & Medicine, Natural Sciences, Society & Culture, Technology

Chart Positions

Natural Sciences 4
Science & Medicine 13

Whether the topic is popcorn or particle physics, you can count on BrainStuff to explore -- and explain -- the everyday science in the world around us.

Why do the plugs on some appliances have two prongs and others have three?

September 26th, 2008

Episode 81 of 1067 episodes

When you look at a normal 120-volt outlet in the United States, there are two vertical slots and then a round hole centered below. Take a look at this HowStuffWorks article to learn why appliance cords are shaped this way.

Featured Podcast

Listen