What is the difference between and iron and microwave?

Answer 1

I will assume you mean a steam iron for pressing clothing, and a microwave oven for cooking food -- and that you want to know the difference in how each one produces heat.

The iron uses a resistive element that heats up when current is passed through. This resistor is not unlike the heating element in a toaster. The principle is: Power is equal to the square of the current times the resistance. The proper value resistor can provide 1200 to 1500 Watts of heating power (to heatup water for steam, and make the ironing plate hot).

The microwave oven uses radio waves with a frequency that is in the range of 2 to 5 billion cycles per second (called micro-waves). At this frequency the wave *length* is about 10 centimeters. This is the proper wavelength to excite water molecules and fat molecules in food to heat them up by direct radiation (not nuclear radiation -- radiowave radiation). The device that produces the 10 centimeter waves is called a magnetron, and it produces these waves at a power level of several 100 watts.

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