Avocados are high in fat. But it's monounsaturated fat, which is a good fat that helps lower bad cholesterol, as long as you eat them in moderation. Avocados have a lot of calories. The recommended serving size is smaller than youâd expect: 1/5 of a medium avocado (or 1 ounce) is 50 calories.
Why do transformers hum? Transformer noise is caused by a phenomenon which causes a piece of magnetic sheet steel to extend itself when magnetized. When the magnetization is taken away, it goes back to its original condition. This phenomenon is scientifically referred to as magnetostriction.
The noise is from the fan that blows air across the magnetron to keep it cool. Microwave ovens also produce a hum. It comes from the transformer, diode and capacitor, which vibrate as they step up the 60-hertz electric power from a wall outlet. SPARKS: Despite common wisdom, metal does not necessarily cause sparking inside a microwave; indeed, the cooking chamber walls are metal.