When the quiz or the teacher asks what “latent” heat is, there is generally some reference to it being hidden heat, which is what the word “latent” means. We then learn that it is heat energy transferred that results in a change of state rather than a temperature change. Later on, we hear a lot […]

Think of it like this: It's a cold, wet, windy day. You can take an umbrella to protect you from the water alone, but that won't deal with the cold (temperature) or the wind (air convection). You can add in a light windbreaker, which will help keep the wind (convection) off. But if you also […]

Why is it called single-phase 240 when there are two opposing phases (or legs)? I wondered why we called two 120v opposing legs “single-phase 240” for years. Then someone pointed out to me that a typical “single-phase” pole transformer only has one power leg entering and two coming out. That freaked me out. How can […]