Microwave ovens have been around since the late 1940s, and their popularity increased in the mid-1970s. Over the years, the cost to purchase a microwave oven has decreased. Today, you can purchase a microwave oven for under $50, as compared to the 1940s price of around $3000.
Microwave ovens produce electromagnetic non-ionizing radiation to cook the food, operating at approximately 3000 volts. They operate in the microwave region in the electromagnetic spectrum at a frequency of 2450 MHz. For domestic use, the microwave oven (see Figures 1-6, 24-1, 24-2, 24-3, and 24-4) is manufactured in different sizes and styles, countertop, hanging, and built-in models with electromechanical or electronic controls.