Contents
Do microwaves have an electric field?
Microwave ovens function by using electromagnetic waves that have a frequency of 2.45 gigahertz. These 2.45 GHz waves are created through the use of a vaccuum tube called a magnetron. Because microwaves are electromagnetic waves, they produce constantly changing electric fields. Water molecules are polar.
Do microwaves create magnetic field?
Microwave radiation creates a magnetic field that oscillates—which means that the field is constantly changing its orientation (direction the positive and negative charges face).
How powerful can a microwave be?
An 800 watt microwave should be powerful enough for most uses. Most microwaves on the market today are rated between 600 to 1100/1200 watts. The higher the watts the faster your food will cook. A lot of recipes for microwave cooking will often require at least 800 watts of power to ensure the food cooks evenly.
What is the role of electric field in microwave cooking?
There is no electric field inside the microwave. There is an electro magnetic wave which consist both magnetic field component and electric field component. These waves are of micro range. They heat the food to cook.
Do microwaves have radiation?
Microwaves are a form of “electromagnetic” radiation; that is, they are waves of electrical and magnetic energy moving together through space. Visible light, microwaves, and radio frequency (RF) radiation are forms of non-ionizing radiation.
How do microwaves interact with matter?
Microwaves interact with matter, microscopically, through its constituent atoms, conduction electrons if present, and atomic magnetic dipoles if present. Electric dipoles absorb greatly microwaves because these cause the electric dipoles to execute damped oscillations at the GHz frequency.
What happens when microwaves are absorbed?
The microwaves are reflected within the metal interior of the oven where they are absorbed by food. Microwaves cause water molecules in food to vibrate, producing heat that cooks the food. The microwave energy is changed to heat as it is absorbed by food, and does not make food “radioactive” or “contaminated.”
Is 1000 watt microwave good?
What microwave wattage do I need? A 1,000-watt microwave will cook quickly and efficiently, so that’s a great baseline. Microwaves with 700 watts or less are slower and may not cook evenly. In general, the higher the wattage, the faster the cooking time.
Is a 1200 watt microwave good?
In general, the higher the wattage, the faster and more evenly your food will cook. Most microwaves sit somewhere between 600 to 1,200 watts. Larger, more expensive microwaves tend to have a higher wattage, so this is a price and size consideration that can strongly influence microwave cooking performance.
Is there an electric field in a microwave oven?
A microwave oven is really no different to any radio transmitter, except its just transmitting its waves inside the metal oven box to protect YOU from the waves. The magnetron creates dipole electromagnetic waves, just like any radio transmitter. The waves are not an “electric field” as you suggested.
Why are electrons pushed to one side in a microwave oven?
Because of their curved motion, the electrons are pushed towards an area where there is excess negative charge in the anode (one side of a cavity.) This excess negative charge is pushed back around the cavity, creating an oscillation of electric and magnetic fields due to a moving charge (Nave 2005).
What are the properties of a microwave oven?
One of the properties of microwaves is that they are reflected off of metal, and so they reflect off of the “stirrer fan” and into the oven chamber. The oven chamber is lined with metal so that the microwaves will continue to bounce around in the chamber until they are absorbed (Heckert 2007).
What causes water molecules to rotate in microwave oven?
Thus, in the presence of the electric field component of a microwave, a force will be applied to both dipoles of the molecule which will cause it to rotate (Heckert 2007). In Figure 4, two water molecules are shown in the positions where the force on their dipoles due to the electric field of a wave is at a minimum.