How Do Metal Rods Short Out The Microwaves !!BETTER!!
The cooking chamber of a microwave oven is always metallic. Eventhe glass door has a metal grid across it to keep the microwaves inside.This metal chamber may be coated with paint or plastic but it is therenonetheless. Without it, the microwaves would leak out and the oven wouldbe hazardous and inefficient. It would cook objects throughout the kitchen.
How do metal rods short out the microwaves
A metal object placed inside the oven deflects these waves away from the food, Ross explains. It sends them jumping around erratically, possibly damaging the interior of the oven. In fact, metal is so good at reflecting this radiation that the window built into the front of microwave ovens contains a fine metallic mesh you can see through, but from which microwaves cannot escape (light comes in small enough wavelengths to slip through, but not microwaves, which measure around 12 centimeters).
The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of cavity resonators, which are small, open cavities in a metal block. Electrons pass by the cavities and cause microwaves to oscillate within, similar to the functioning of a whistle producing a tone when excited by an air stream blown past its opening. The resonant frequency of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a klystron or a traveling-wave tube (TWT), the magnetron cannot function as an amplifier for increasing the intensity of an applied microwave signal; the magnetron serves solely as an oscillator, generating a microwave signal from direct current electricity supplied to the vacuum tube.
Mechanically, the cavity magnetron consists of a large, solid cylinder of metal with a hole drilled through the centre of the circular face. A wire acting as the cathode is run down the center of this hole, and the metal block itself forms the anode. Around this hole, known as the "interaction space", are a number of similar holes ("resonators") drilled parallel to the interaction space, connected to the interaction space by a short channel. The resulting block looks something like the cylinder on a revolver, with a somewhat larger central hole. Early models were cut using Colt pistol jigs. Remembering that in an AC circuit the electrons travel along the surface, not the core, of the conductor, the parallel sides of the slot acts as a capacitor while the round holes form an inductor: an LC circuit made of solid copper, with the resonant frequency defined entirely by its dimensions.
All cavity magnetrons consist of a heated cylindrical cathode at a high (continuous or pulsed) negative potential created by a high-voltage, direct-current power supply. The cathode is placed in the center of an evacuated, lobed, circular metal chamber. The walls of the chamber are the anode of the tube. A magnetic field parallel to the axis of the cavity is imposed by a permanent magnet. The electrons initially move radially outward from the cathode attracted by the electric field of the anode walls. The magnetic field causes the electrons to spiral outward in a circular path, a consequence of the Lorentz force. Spaced around the rim of the chamber are cylindrical cavities. Slots are cut along the length of the cavities that open into the central, common cavity space. As electrons sweep past these slots, they induce a high-frequency radio field in each resonant cavity, which in turn causes the electrons to bunch into groups. A portion of the radio frequency energy is extracted by a short coupling loop that is connected to a waveguide (a metal tube, usually of rectangular cross section). The waveguide directs the extracted RF energy to the load, which may be a cooking chamber in a microwave oven or a high-gain antenna in the case of radar.
In microwave-excited lighting systems, such as a sulfur lamp, a magnetron provides the microwave field that is passed through a waveguide to the lighting cavity containing the light-emitting substance (e.g., sulfur, metal halides, etc.). Although efficient, these lamps are much more complex than other methods of lighting and therefore not commonly used.More modern variants use HEMTs or GaN-on-SiC power semiconductor devices to generate the microwaves, which are substantially less complex and can be adjusted to maximize light output using a PID controller.
The radioactive material that fuels a nuclear power plant is contained in ceramic fuel pellets that are capable of withstanding thousands of degrees of heat. These fuel pellets are then encased in hollow metal rods that help keep the material from interacting with the water that cools the reactor. In addition, the reactor's thick metal walls and piping, as well as a massive reinforced concrete containment structure, are designed to keep the coolant, fuel, and associated radiation isolated from the environment.
The metal reflects the microwave, which crashes into other microwaves, causing the amplitude of the microwave to increase. A bigger amplitude means more energy and more heat, which could cause a fire or damage the metal housing of your microwave oven. Ask my three-year-old son, who decided to try his hand at working the microwave!
Microwaves are a form of electromagnetic radiation created by a device called a magnetron. The metal in the walls and door of a microwave oven are safety measures. They keep the microwaves from escaping and cooking other objects, such as YOU!
The metal inside a microwave oven reflects the microwaves and focuses them on the food to be cooked. The microwaves get absorbed by certain molecules within food. For example, water molecules within food primarily absorb microwaves and begin to move back and forth, generating heat that cooks the food.
Metals, such as forks, knives, and spoons, are great conductors of electricity, because they contain lots of electrons that move about freely. When microwaves hit metal objects, they get reflected, which can cause problems.
If there isn't sufficient material in the microwave oven to absorb the reflected microwaves, arcing between the metal object and another part of the microwave oven can occur. This looks like a miniature bolt of lightning when it occurs, and it can seriously damage the microwave oven by starting a fire, burning a hole in the wall of the microwave oven, destroying the magnetron, or damaging sensitive electrical components.
Good question! Let's take a closer look at the article: "Metals, such as forks, knives, and spoons, are great conductors of electricity, because they contain lots of electrons that move about freely. When microwaves hit metal objects, they get reflected, which can cause problems. If there isn't sufficient material in the microwave oven to absorb the reflected microwaves, arcing between the metal object and another part of the microwave oven can occur. " Hope that helps, Mr. Cena!