Microwave Oven and it’s working
Microwave ovens are very common in our kitchens nowadays. We cook or heat the food at a blazing fast speed thanks to electromagnetic radiation and electricity. But sometimes, we really wonder how does a microwave oven work? Here we have explained the working principle of the microwave oven.
Brief history of microwave oven.
American engineer Percy Spencer invented the microwave oven during the World War 2. Actually, the real credit goes to the development of cavity magnetron in the UK. Cavity Magnetron produces small wavelengths. These wavelengths are extremely suitable for microwave oven. However, these units were huge and not suitable for home use.
Furthermore, Sharp Corporation introduced the first commercial microwave oven in 1970. These microwave ovens were small and could easily accommodate in homes. In addition, the cost of these microwaves was low compared to previous versions. Since then, the microwave oven is part of every kitchen around the world.
How do microwave oven work?
First of all, microwave ovens heat the food from inside by passing electromagnetic radiation through the food. The source of the electromagnetic radiation is the magnetron inside the microwave oven. These radiations are non-ionizing radiations. In addition, the frequency of the microwaves is higher than radio waves but lower than infrared light.
The magnetron takes electricity from the power grid and converts it into microwaves having a frequency higher than radio waves. This magnetron then directs these waves over a waveguide.
Furthermore, the food inside the microwave continuously rotates in a circular motion. So, it ensures even heating of the food. The microwaves inside the metal compartment of the oven bounce in various directions. The reflective surfaces inside the oven keep them bouncing in different directions. During this movement, the waves pass through the food.
The waves while traveling through the food vibrate the molecules in the food. As more and more waves pass through the molecules, they began vibrating very rapidly and produce heat. Thus, these waves pass the energy to the food making it hot.
In addition, the microwaves heat up the water molecules at faster rates than any other molecules. So,
The microwaves can’t penetrate deep inside the food. The inside of the food is generally cooked by the conduction. This means you have to wait until temperatures inside the food reach cooking temperature by conduction and not by microwaves. We have to keep this in mind. Otherwise, the food inside will remain uncooked while the outer layer appears to be ready.
The safety and microwaves
The microwave oven has safety measures in place to avoid microwaves going outside of the microwave oven. The holes to the microwave wall won’t pass any waves outside because the waves are large and won’t go out. Another safety measure is the automatic turning off of the magnetron when you open the door accidentally or intentionally. Thus, it quickly stops producing microwaves.
Furthermore, by any means the waves come out, they don’t harm human tissues. As the waves move outside the oven, the energy levels of the waves drop with distance. Hence, they don’t have enough power to harm human tissue when the waves come out. But, you should replace or repair the microwave if you find it leaking the waves outside, on to be safer side.
Speed and efficiency.
The microwave oven heats the food faster and that is its biggest advantage. You also think that it will be more efficient as it requires less time to cook the food. Unfortunately, that is not the case. The microwave oven requires lots of electricity as magnetron itself is not that efficient when it comes to conversion to microwaves.
In addition, you will require an additional motor to turn the food inside in a circular motion. You will also need to keep magnetron cool. Magnetron heats up fairly quickly and may require an additional fan to cool itself. All this addition almost comes closer to the efficiency of the traditional oven. So, there is not much difference when it comes to efficiency. But yes, you can cook or heat the food faster in the microwave than a traditional oven.
In conclusion, the microwave oven has changed the way we cook food. It also brought more opportunities in the food packaging industry. So now, you can have your delicious food ready on the table in a matter of minutes.
Watch working of microwave oven:
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