How microwave oven works?? ZHI LI, HUI LI, RUI SHI, JIAJIE HUANG I believe that all of us are familiar with microwave ovens, since we more or less have the experience of making pop-corns, reheating previously-bought foods, maybe Big Bowl noodles, or heating fast food in our dorms; however few of us know how microwaves work. Don’t worry, this project will clearly show you. Why microwave oven is so popular?? Because microwave ovens heat foods quickly and efficiently, they are one of the most popular kitchen appliances. A microwave oven converts only part of its electrical input into microwave energy. For example, an ordinary microwave oven, like one pursued at WalMart, consumes 1100 W of electricity in producing 700 W of microwave power, an efficiency of 64%. How microwave oven works?? As the name implies, the microwave oven heats the food with microwave radiation. Such radiation is non-ionizing and has a frequency of 2.45 GHz and a wavelength of 122mm. As what we learn in class, magnetic field is the magnetic force per tiny dipole. Similar to the concept, the molecules in food are tiny dipoles but are electrical. Therefore, they have both positive and negative charge on them, which concludes as neutral. When the microwave goes across the food, the electrical field on microwave has an effect on the food molecules. We once discuss that magnetic fields make charges move. As a result, the molecules in food will move due to the electrical field. Then they will run into other molecules into motion too, and the motion produces energy, heat. Let's see what is inside and how it works!!! http://science.discovery. com/videos/deconstructed-how-microwaveovens-work.html But.... Attention!!! As we may notice, more and more people claim that exposure to microwaves can cause cancer and other diseases, which are obviously undesirable. But according to the United States Food and Drug Administration's Center for Devices and Radiological Health, a U.S. Federal Standard limits the amount of microwaves that can leak from an oven throughout its lifetime to 5 milliwatts of microwave radiation per square centimeter at approximately 5 cm (2 in)--- ---from the surface of the oven. This is far below the exposure level currently considered to be harmful to human health. So the radiation produced by a microwave does not have the cancer risks associated with ionizing radiation such as X-rays and high-energy particles. We can use it with ease and joy. The microwave oven in the future ● more efficient Intellowave Cuisine Heat Sensor This technology offers no less than superior cooking, reheating and defrosting for a wide range of food items. Goldstar microwave ovens are designed with a sensor chip that can detect humidity levels. Based from the information, the microwave automatically adjusts the cooking time and power level that is needed to prepare the food and so, avoids wasting energy. ● more smart In order to take advantage of the popularity of the Internet, the microwave industry has introduced the so-called Internet microwave oven. The oven can be connected to the Internet to access recipes and other cooking information for automatic food preparation. Several companies plan to market their products in the near future. ● more powerful The power of Microwave has increased dramatically in recent years And scientist predict that it will reach 3000watts in the next 5 years- which is nearly 2 times more powerful than current product. Insight Since human realized the existence of wave, we have used wave in many aspects and have invented lots of fantastic products like microwave ovens, rider and B ultrasonic. Unfortunately, as many scientists admit, by now human long can utilize a very small parts of waves. But that also means that wave applications still have huge potentials, we can believed that in the future wave technologies will definitely enhance our satisfactions of lives. Reference http://www.novelguide. com/a/discover/cdsg_02/cdsg_02_00032.html http://en.wikipedia.org/wiki/Microwave_oven