First law of Thermodynamics

First law of Thermodynamics: During Cyclic Thermodynamics process the net heat supplied to the system by the surroundings is equal to the net work done by the system on the surroundings. Or Heat and work are mutually convertible. Or It is impossible to construct a perpetual motion machine of first kind. i.e.                         cyclic ∫dQ = […]

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Equations of motion

Equations of motion: The three equations of motion are v = u + at v2 – u2 = 2aS S = ut + ½ at2 Where u = initial velocity                 v = final velocity                 S = distance covered by the object                 t = time taken to cover the distance                 a = acceleration due […]

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Entropy

Entropy: It is defined as the degree of randomness or disorder due to rise in temperature in the system. The more the heat absorbed by the system the more disordered it becomes or more entropy it has. When the heat is absorbed by the system at low temperature it becomes more disordered as compare to […]

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Energy flow in ecosystem

Energy flow in ecosystem: Biological activity requires utilization of energy, which comes from the sun. Solar energy is converted into chemical energy by the process of photosynthesis. This chemical energy is then transformed into mechanical and heat forms during metabolic activities. The flow of energy in the biological world takes place from the sun to […]

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Endangered species

Endangered species: The International Union for Conservation of Nature and Natural Resources (IUCN) has published the IUCN Red List of threatened species. The objectives of this list are: Identification and documentation of endangered species Creating awareness about the importance of threatened species Preparing a global index for the decline of biodiversity This list categories various […]

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Electron beam machining (EBM)

Electron beam machining (EBM): A high velocity beam of electrons is focused magnetically on a very small area of work piece. The high velocity beam raises the temperature locally above the melting point as the kinetic energy of high velocity electrons is converted into heat energy. The material melts and vaporizes at the point of […]

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Electro discharge machining (EDM)

Electro discharge machining (EDM): We use electrical energy to cut the material to final shape and size. The work piece (anode) and tool (cathode) are separated by a dielectric fluid medium. The workpiece is made anode (positive) and tool is made cathode (negative) in order to remove maximum metal and minimum wear on tool.   […]

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Electro chemical machining (ECM)

Electro chemical machining (ECM): This process is generally used for hard materials which are difficult to machine using conventional methods. The process is used for mass production. The removal of material takes place due to atomic dissolution of work material. Material removal rate is governed by Faraday laws of electrolysis. Material removal rate is quite […]

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Electro chemical grinding

Electro chemical grinding (ECG): The Electrochemical grinding (ECG) and Electro-chemical machining (ECM) are similar instead of tool used in Electro-chemical grinding is an abrasive grinding wheel in place of tool. The metal is removed both by Electro-chemical decomposition (90%) and abrasion of the metal (10%). A non corrosive salt solution is used as an electrolyte. […]

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Elastic Constants

Elastic Constants: Young’s Modulus or Modulus of Elasticity: It is the ratio between compressive stress and compressive strain or tensile stress and tensile strain. It is denoted by ‘E’. Its units are GN/m2. E = stress/stain = σ/ε = σt/εt = σc/εc Modulus of Rigidity or Shear Modulus of Elasticity: It is the ratio of shear stress (τ) […]

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