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Modern Physics

uses of laser in daily life

List of uses of laser and applications in the field of medicine,industry and agriculture : Laser beams are used as surgical tool for “welding”detached retinas. The narrow intense beam of the laser can be used to destroy tissue in a localized area. The organelles with a living cell have been destroyed by using laser to study how the absence of ...

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Uses of x ray waves

Uses of X rays in field of medical ,engineering,industry are given: 1:Radio Therapy X-rays kill the diseased tissues of the body.Hence they are used to λ cure intractable skin diseases,malignant tumours etc.If the affected part is superficial soft rays are applied and for deep seated organs hard rays are used. 2:Engineering Because of their high penetrating power they are used ti ...

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What is plasma physics

“The branch of physics which deals with the study of the properties of plasma is known as plasma physics.” Plasma definition: A highly ionised gas is regarded as a fourth state of matter called the plasma state.It is regarded as fourth state of matter since it is not solid,liquid or gas in usual sense. How to create plasma? The kinetic ...

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Is an electron a particle or a wave?

In 1924,de Broglie proposed that particle acts as a wave and wave acts as a particle. Davisson and Germer experimentally confirmed the wave nature of electron.They showed that electrons are diffracted from metallic crystal in the same manner as x-rays and other wave.Hence electrons show wave like properties.J.J Thomson while measuring e/m of electron showed that electron is a particle.Thus ...

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Does a photon have a de Broglie wavelength?

Yes a photon has de Broglie wavelength.In 1924,Louis de Broglie proposed that a particle must also act like wave,in silmilar way,wave behave like particles. In de Broglie hypothesis an electromagnetic wave is the de-Broglie wave for a photon moving with speed c.According to de-Broglie ,the wavelength of the photon is given by the relation: λ = h/p Where P is ...

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What are X-rays?

What are X rays made of: X-rays are the electromagnetic waves which are emitted by the atoms of those metals which have large atomic number,large number of protons in their nuclei so that the pull of the nuclei on their electrons is very large.When an electron of K or L shell of such an atom is displaced from these shells ...

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alpha beta and gamma radiation

Discovery of Radioactivity: In the March 1896 Henri Becquerel announced the discovery of radioactivity similar to X-rays.Although rays (X-rays) had been discovered less than four month earlier it was already known that X-rays come from the fluorescence wall of the discharge tube and thus it was thought that fluorescence and phosphorescence might be responsible for them. Becquerel known that Uranium ...

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What is thermal radiation

Thermal radiation: Radiation emitted by such a body due to its temperature is called thermal radiation.All bodies not only emit such radiation but also absorb it from their surroundings.If the rate of absorption and emission from a body become equal ,the body is said to be in thermal equilibrium with its surroundings. The spectrum of thermal radiation from a hot ...

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What is Photovoltaic effect

Photovoltaic effect: An effect arising when a junction exists between two dissimilar materials and one of the materials is exposed to electromagnetic radiation,usually in the range near ultraviolet to infrared.The two materials may,for example,be a metal and a semiconductor or two semiconductors of opposite polarity,the combination forming a Schottky barrier and a P-N junction respectively.A forward voltage appears across the ...

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What instrument is used to measure atmospheric pressure?

Barometer is an instrument used to measure atmospheric pressure. How can we measure atmospheric pressure by mercury barometer? Mercury barometers consist of a glass tube about 80 cm long,closed at one end.The tube is filled with mercury and then placed,open end downward,in a reservoir of mercury.As the atmospheric pressure changes ,the level of the mercury changes and to a lesser ...

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