Electromagnetic waves are waves created by cause of vibrations between electric and magnetic fields. Specifically, the electromagnetic wave has both magnetic and electric fields swinging. Electromagnetic waves are used to transfer either short, long or FM radio waves, and the TV, phone, wireless or energy signals. They are also in charge for transmitting energy in the form of microwaves, infrared radiation, visible light, ultraviolet light, X-ray, and gamma rays.
An electromagnetic wave is found when the electric field meets the magnetic field. It is known as electromagnetic waves. The electrical and magnetic fields of electromagnetic waves at the right angle to the exact angle of each other. It is also straight to the EM wave direction. Electric charge vibration creates electromagnetic waves. This oscillation produces a wave that has both electric and magnetic components. Electromagnetic waves carrying energy through vacuum at speeds of 3.00 x 108 m / s. The transmission of electromagnetic waves through material media take place at net speeds less than 3.00 x 108 m / s. They are not guarded by electric fields, or by magnetic fields. However, they may show distortion or divergence. Electromagnetic waves can move through anything, it can be air, solid or vacuum material. It does not need the medium to propagate or travel from one place to another. Mechanical waves such as sound waves or water waves, require a medium to move. The EM wave is a ‘transverse’ wave. This means they are measured by the amplitude or altitude and the wavelength which is the area between the highest or lowest point two successive waves. The highest point of the wave is known as ‘peak’, while the lowest point is known as ‘trough’. Electromagnetic waves can be divided into various frequencies. This is known as the electromagnetic spectrum. Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, and so forth.
1.2 – ELECTROMAGNETIC IN DEVICE
What is a destructive area, your rock concert and your front door have in
common? They each use electromagnetic devices that produce magnetic fields
through electricity use. Destructive pathways use powerful electromagnet to
move pieces of iron or entire trains from one place to another. Your favorite
band uses electromagnetic to amplify the sound that comes out of its speakers.
And when someone rings your doorbell, a small electromagnet pulls metal lumps
against the bell.
Mechanically, the electromagnet is easy enough. It consists of a
conductive wire length, usually copper, wrapped in a piece of metal. Just like
Frankenstein’s monster, it looks like more than a collection of loose gadgets
until electricity goes into the picture. But you do not have to wait for a
storm to bring electromagnet to life. The current is introduced, either from
batteries or other electrical sources, and flows through the wires. This
creates a magnetic field around a coiled wire, magnetizing metal as if it were
a permanent magnet. Electromagnetic is useful because you can turn on and off
the magnet by completing or interrupting the respective circuit.
Before we go further, we must discuss how electromagnetic is different
from your “fixed” magnets, such as those that hold your Popsicle art
into the refrigerator. As you know, the magnets have two pillars,
“north” and “south”, and attract objects made of iron or
some of its combinations. As poles evict and conflictingly attractive (ah,
junction of romance and physics). For example, if you have two bar magnets with
the ends marked “north” and “south,” the northern tip of
one magnet will pull the other end of the south. On the contrary, the northern
tip of one magnet will repel the other end of the north and, the south will deflect
south. Electromagnetic is the same way, except it is “temporary” a
magnetic field only exists when the electric current flows.
Doorbell is a good example of how electromagnetic can be used in
applications where permanent magnets will not make sense. When the guest pushes
the button at the front door, the electronic circuit inside the doorbell closes
the electric loop, which means the circuit is finished and “turned
on.” The closed circuit allows the flow of electricity to flow, creating a
magnetic field and causing the clapper to become a magnet. The hardware of most
door workshops consists of metal bells and metal wards which, when magnetic
charges cause them to gather together, you hear the sound inside and you can
answer the door. The bell rings, the guest releases the button, the open
circuit and the doorbell stops from the infernal ring. This on-demand magnetism
is what makes electromagnetic so useful.
– PRINCIPLE OF ELECTROMAGNETIC IN MICROWAVE
Microwave ovens work by producing microwaves, this is a kind of electromagnetic wave such as radio waves, infrared or visible light. They are created by a device called magnetron and left from the hole to the right. The components called magnetron generate microwaves from electricity in the microwave. To drive the magnetron, the transformer converts standard household electricity from a wall socket of 120 volts to about 4,000 volts or higher.
The voltage heats the filaments at the center of
the magnetron that boils off electron. The electrons are whirled around by two
ring magnets. The microwaves will reflect from the two sides of the metal
oven. This creates wave at a specific frequency, typically 2.45 gigahertz.
Microwave wavelengths are tuned to make standing
waves. Here’s where you get two waves, one goes in every direction, it
interacts to make some areas where there is a huge vibration and the other
where there is not.
This means there is a place where the microwave is very fierce, where the molecule will vibrate strongly until it is heated strongly. Others where microwaves are weak. The area is separated by half the wavelength. Therefore, there is a turntable in the microwave, otherwise the portion of your food will mature, and the other will remain crude.
If you put bread in the microwave, the first butter will melt where the microwave is the most intense, so the distance between it will be half the wavelength.
What Has the Wavelength Got to Do
with The Speed of Light?
Your microwave oven produces a microwave that vibrates at a certain frequency, it is written behind your microwave.The wavelength depends on how fast the vibrating waves or the frequency and how fast they move because they are the kind of light, the speed of light.
So, this means if the wave has a 100Hz frequency it will wavelength 100 times in one moment. Wave speed is frequency × wavelength.Because the microwave is the kind of light you just measured the speed of light in your kitchen!
– MICROWAVE OVEN
Microwave is efficient and can cook food quickly, with no heat sources
visible as they direct heat energy into molecules that are tiny particles
inside the food. Microwave heaters like hot sun heat your face with radiation.
When baking the oven, you can feel the heat, and above the kitchen, you can see
the fire emanating from the surface. When you turn on the microwave, it
produces a radiation wave that penetrates your food, breaks down water
molecules and makes them fur with energy.
Microwave ovens are a type of electromagnetic radiation, such as radio waves, ultraviolet radiation, X-rays and gamma rays. Microwave has a wide range of applications, including communication, radar and, probably most famous by most people, cooking. Electromagnetic radiation is transmitted in waves or particles at different wavelengths and frequencies. It is an invisible electric and magnetic pattern that penetrates the air with 300,000 km of light or 186,000 miles per second. Although radio waves can be very long with a few kilometers or kilometers between wave waves and beyond, they can also be small, microwaves are the shortest radio waves and microwaves that cook food in your oven just 12 cm, about 5 inches long.
Despite its small size, microwave ovens carry a lot of energy. A microwave disadvantage is that they can damage living cells and tissues. Microwave radiation can heat the body tissues in the same way it warms up food. Exposure to significant levels of microwave can cause painful burning. Two areas of the body, eyes, and testes, are very susceptible to radio frequency heating because there is little blood flow in them to bear excess heat. In addition, lenses are extremely sensitive to heat and exposure to high elevation levels can cause cataracts. Burns and cataracts can only be caused by exposure to many microwave radiation. Therefore, the microwave oven is surrounded by a strong metal box that does not allow the waves to escape. In normal operation, the microwave oven is safe. Even so, microwave ovens can be very dangerous, so do not waste yourself in the microwave.
– HOW MICROWAVE WORKS
This is the way how electricity change into heat.
1. First thing is metal box which is located inside the microwave. This metal
box function as generator called magnetron. When we turn the plug on, magnetron
take power from electricity and converts into high power about 12cm (4.7) radio
2. The magnetron spread the wave into the food compartment which is called wave
3. Food can cook evenly because it placed on turntable and spinning slowly.
4. Just like a mirror, the wave in a wave guide can bounce back surrounding.
However, when the wave straight to the food, it can penetrate inside the food
just like radio wave can pass to the wall of your house. So, this is why food
can cook evenly because the molecules inside the food vibrates quickly.
5. The faster molecules vibrate, the hotter the food become. This is how
microwave transfer their energy into the food by using molecules.
– Role of microwave
– One of the role of microwave is it can reheat the food until the food become
warm without soggy. It just took only a second and it can turn the food like
original form. This is a reason why microwave is very popular to use, not only
in a kitchen, it used widely in a bakery or another food joints. If food is
less, it just took one into two minutes only, if more quantity, it can took
about ten to fifteen minutes.
– One of the main function that can applied to microwave is defrosting. Defrosting
is a thawing the food before cooking it. But in microwave, we can defrost our
food just in a minute for example meat and vegetables. By using this function, we also can retain
the food in original form and nutrients and also can avoid wastage of water by
washing it, draining, and time.
Boiling and steaming
– We can boiling and steaming the food either using stove or microwave. But the
different is, microwave boiling the food evenly, while stove not. Any other
foods or vegetables, we can be boiling or steaming according how long the time
we set up and to make sure the nutrients still retain in the foods. Based on
experiment vision, scientist do more prefer to use microwave than stove to boil
or steam your food
There have a lot of things that
we can found in physics. The example is electromagnetic radiation. Some called
it EM, either is EMR. EMR is a wave of photon that carrying electromagnetic
radian energy through space over time. Its include radio waves, microwaves,
infrared, visible light, ultraviolet, x-rays and gamma rays.
In EMR, there have a good side and bad side that we can list from EMR. The bad
side is EMR can affect our healthy and our body based on radiation emits either
in electric, magnetic, wireless/RF/microwave/WiFi or ionizing. These technology
influences our healthy based on how far we are living and how frequent we use
in these technology.
However, there also have many types of good things in EMR such as telephone,
navigation, radio, television, medical scanner, Wi-Fi and the things what we
discussed in the topic is cooking & heat which is microwave oven. Microwave
oven is widely used in the world either in the kitchen, stall, market or food
court. This is because microwave oven can save time, easy to heat food, easy to
clean, no need to keep a watch, retains nutrients and vitamins in the food.
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3. Marshall Brain & Lance Looper “How
Electromagnets Work” 1 April 2000.
4. https://www.emaze.com/@AWRZCLQL/THE-ELECTROMAGNETIC- SPECTRUM