Microwaves are electromagnetic radiations. They are used for generating heat and are also for communications. Longer microwaves like those used in o microwave oven are used to cook food microwave oven ore used to cookf microwaves are used in communicatio weather forecasts. Microwaves,oven which or crowaves, which are used for radars, are just a few centimetres Long.
Short and long microwaves
Each wave has a certain shape and length, The distance between peaks or high points is called wavelength. Microwaves are of two basic depending on their wavelengths-short and
long microwaves. Short microwaves have show wavelengths that can be measured in centimeters while the long microwaves have wavelengths of about a foot
The existence of microwaves was predicted by a Scottish scientist, James Clerk Maxwell, in 1864. His equations predicted the existence of microwaves. Twenty-four years later, in 1888, Heinrich Hertz demonstrated that Maxwell was right about the existence of microwaves. Hertz built a device that produced and detected microwaves. In 1894, the Indian scientist, n J. C. Bose, publicly demonstrated the wireless control of a bell using
microwaves with wavelengths in the range of 0.5-2.5 cm. He also conducted research on the propagation of microwaves.
n scientist, Guglielmo Marconi, repeate Italian Hertz microwave the small distances but across continents. after the transmission of the first signal, Marconi set up the world’s
frst microwave link for the experiments. He showed that radio and ave transmissions were possible not just for Thirty years trans-Atlantic Vatican. Marconi received the Nobel Prize for physics in 1909. He is also known as the father of radio.
importance of microwaves
Microwaves can penetrate clouds, snow, haze, and smoke. They are very useful for transmitting information from one place to another.
Radio communications using frequencies between approximately 1 GHz and 1,000 GHz is called microwave radio. Many broadcasting and telecommunication transmissions use microwave radio because of the shorter wavelength and larger bandwidth of the microwave spectrum.
A microwave link is a transmission device. It allows video, audio, and data transmissions using radio waves. Transmissions can be sent between two locations that may be a few metres to several kilometres apart Television broadcasters use microwave link to transmit
television programmes. A microwave link is commonly used in television news and sports events to transmit a signal from a remote location to a television station. The mobile units, called outside broadcast vans (OB vans) use microwave links to transmit live programmes
back to the studio for broadcast
The magnetron is a tube that produces microwave energy. It was invented by Albert Hull in the 1920s. In the late 1930s and early 1940s, Harry Boot and John Randall developed it further. Magnetron was used by the United States during the World War II to detect ships. Later it was used to manufacture microwave ovens in the late 1940s.
Cosmic microwave background
Cosmic microwave background (CMB) is a form of radiation that fills the whole universe. The existence of CMB radiation was first observed by accident in 1965 by Arno Penzias and Robert Wilson at the Bell Telephone Laboratories in Murray Hill, New Jersey, USA
The invention of the microwave oven was one of the important applications of microwaves
The microwave oven uses microwaves to cook or heat food. Percy Spencer, an American
engineer working with the Raytheon Company, invented the first microwave oven while
working with the magnetron. Magnetron is a device that produces microwave radiation.
In 1946, he discovered that microwaves could be used to cook food fast. The first food to
be inadvertently heated by microwaves was a chocolate bar that Dr Spencer had in his
pocket while he was experimenting with the magnetron. He then experimented with
popcorn kernels and an egg. In 1947, the first commercial oven was sold by the