KNOW PHYSICS

INTRODUCTION What is Quantum mechanics?| Quantum Mechanics is the theory which attempts to explain the behaviour  of matter and interaction with energy on the scale of atoms and atomic particles i.e., particles of the size of the order of   1/10¹⁰ metres. Phenomena such as motion of mechanical objects involving distances larger than about  1/10⁶ metres can be explained satisfactorily by laws of classical theoretical physics which is based on the following basic laws :  1) Newton's Laws of motion,  2) Newton's inverse square law of gravitational attraction between two bodies,  3) Coulomb's inverse square law of attraction or repulsion between two electrically charged bodies,  4) The law of force on a moving charge in a magnetic field, i.e., the Lorentz force. However, certain phenomena such as spectral distribution of energy in blackbody radiation, Photoelectric effect etc; and phenomena involving distances of the order of 1/10¹⁰ metres could not b

X-Rays  Introduction X rays discovered by William Roentgen in 1895 honoured by Nobel Prize in 1901. Basically are high energy photons (1- 100Kev) or electro-magnetic radiation, having a very short wavelength of the order of 1A⁰. Typical x-ray wavelength lies between the range of  1 A⁰ and 100A⁰. Accordingly they are classified into hard X-rays and soft X-rays.  Uses of X rays are multifold. Usually they are used in surgery, radiotherapy, engineering, industry, detective department, scientific research and so many other areas. Hence, the name X-rays is popularly known even to a common man. Production Of X-RAYS The modern X-ray tube was designed by Dr.Coolidge and is known after his name as coolidge tube. It is widely used for commercial and medical purposes. Construction and working of Coolidge Tube The construction of coolidge tube to produce X-rays is schematically shown below. The cathode C consists of a tungsten filament  heated by passing a current th

STATISTICAL MECHANICS: A BRIEF HISTORY Statistical mechanics was initiated in 1870 with the work of Austrian physicist Ludwig Boltzmann, much of which was collectively published in Boltzmann's 1896 lectures on gas theory. Statistical mechanics provided a molecular level interpretation of microscopic thermodynamic quantities such as eork, heat, free energy and entropy. The study of statistical physics is mainly classified into categories. These are: Classical statistics or Maxwell-Boltzmann statistics. Quantum statistics or Bose -Einstein and Fermi-Dirac statistics. STATISTICAL BASIS Statistics is that branch of science which deals with the collection, classification and tabulation of numerical data as the basis of explanation, description and comparison of various phenomenon. When statistical concepts are applied to physics, the new branch that emerges is called statistical physics. Statistical physics deals with macroscopic systems. i.e. the system consisting

What is force? Force is a word which we have all heard about. When you push or pull some object you exert a force on it. If you put a body you exert a force away from yourself; when you pull, you exert a force towards yourself. When you hold a heavy block in your hand you exert a large force; when you hold a light block, you exert a small force. Can non living bodies exert a force? Yes non living bodies can also exert force. If we stand in a great Storm, we feel that the wind is exerting a force on us. When we suspend a heavy block from a rope, the rope holds the block just as a man can hold it in air. When we comb our dry hair and bring the comb close to small pieces of paper, the pieces jump to the comb. The comb has attracted the paper pieces i.e. the comb has exerted force on the pieces. Force is an interaction between two objects.The SI unit for measuring the force is called a newton. Approximately, it is the force needed to hold a body of mass 102 gram near the Earth&

Here are some of the latest researches , experiments and observations in the field of Physics. Enjoy! 1) Quantum 'fifth state of matter' observed in space for first time! JUNE 11, 2020| A team of NASA scientists unveiled the first results from Bose-Einstein condensates experiments aboard the International Space Station, where particles can be manipulated free from the constraints of gravity. Scientists have observed the fifth state of matter in space for the first time, offering unprecedented insight that could help solve some of the quantum universe's most intractable conundrums. 2) Black holes? They are like a hologram! JUNE 4, 2020| According to new research by SISSA(International School of Advanced Studies), ICTP and INFN, black holes could be like holograms, in which all the information to produce a three-dimensional image is encoded in a two-dimensional surface. What researchers have done is apply the theory of the holographic principle t

Liquids have a property that their free surface behaves like a stretched elastic membrane and has a natural tendency to contract, i.e , the free surface of a liquid tends to occupy a minimum surface area. This property of liquids is called as surface tension. Some experiments and examples related to Surface Tension- Let us consider a frame. There is a closed loop thread attached with the frame loosely, so that it can change its shape. Now dip the frame in soap solution. Break the film created inside the loop. After breaking the film, it is observed that the thread occupies a shape  of a circle. REASON - The surface tension tends to make the surface area of the film as minimum as possible. And for a given length of thread, the surface area of circle is maximum, which eventually decreases the surface area of the film to minimum. Brush in water-  When we put brush in water, the brush hair can be seen separately in water. But when we take out the brush out of the water,

  Basic Definition   PHOTOELECTRIC EFFECT| Photoelectric effect is the emission of electrons or other free carriers when electromagnetic radiation, like light, hits a material. Electrons emitted in this manner can be called photoelectrons. This phenomenon is commonly studied in electronicphysics and in fields of chemistry such as quantum chemistry and electrochemistry. A Brief History - This effect was observed earlier before Albert Einstein gave the theory for it.  In 1839, Alexandre Edmond Becquerel discovered the photovoltaic effect while studying the effect of light on electrolytic cells. Though not equivalent to photoelectric effect. The first of these phenomena was discovered by Heinrich Hertz and Wilhelm Hallwachsin 1887.  In 1887, Heinrich Hertz observed the photoelectric effect and the production and reception of electromagnetic waves. The second was first announced by Philipp Lenard in 1900. Albert Einstein's 1905 research paper ALBER