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Author Archives: admin

entropy in thermodynamics with examples and properties

What is Entropy in thermodynamics? The concept of entropy was introduced into the study of thermodynamics by Rudolph Clausius in 1856 to give a quantitative basis for the second law. It provides another variable to describe the state of a system to go along with pressure, volume, temperature and internal energy. If a system undergoes a reversible process during which ...

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Energy stored in a capacitor equation derivation and problems

Energy stored in a capacitor equation Consider a capacitor with the capacitance ‘C’ ,which is connected to the battery of emf ‘V’ .If ‘dq’ charge is transferred from one plate to other,then the work done ‘dW’ will be: dW =V dq This work done is stored in the form of electric potential energy ‘dU’ dU =V dq When the capacitor ...

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Difference between polar and non polar dielectric materials

Capacitance with dielectric formula Consider a parallel plate capacitor which is connected with a battery of emf ‘V’ .Let ‘A’ is the area of each plate and ‘d’  is separation between the plates. If ‘q’ charge is stored in the capacitor when there is vacuum or air as medium between the plates ,then: q= CV Where ‘C’ is the capacitance ...

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Atmospheric pressure:Definition,formula & applications

Atmospheric Pressure The Earth is surrounded by a cover of air called atmosphere. It extends to a few hundred kilometers above sea level. Just as certain sea creatures live at the bottom of ocean, we live at the bottom of a huge ocean of air. Air is a mixture of gases. The density of air in the atmosphere is not ...

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Difference between thermistor and thermocouples

Thermistor definition A thermistor is a type of  variable resistor that is temperature sensitive . How thermistor works? When its temperature coefficient is negative,the resistance changes inversely with temperature. When its temperature coefficient is positive the resistance changes directly with temperature. The resistance of a photo-conductive cell changes with a change in light intensity.This cell also has a negative temperature coefficient. Symbols for ...

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Second equation of motion derivation with graphical method

Second equation of motion Derivation Suppose a body is moving with initial velocity “Vi” after time t its velocity becomes Vf.The distance covered by the body is “S”.The acceleration of the body is represented by a. Explanation: Consider the speed time graph in which the initial velocity “Vi” of the body is represented by “OA”.After a time interval, OC the ...

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formula for total capacitance in series and parallel combination

Formula of equivalent capacitance in series Series combination when capacitors are connected in series,the total capacitance is less than the smallest capacitance value because the effective plate separation increases.The calculation of total series capacitance is analogous to the calculation of total resistance of parallel resistors. This type of combination has the following characteristics: Each capacitor has the same charge across ...

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Newton’s law of universal gravitation formula

Newton’s law of gravitation can be stated as:”Everybody in the universe attracts every other body with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.” Newton went a step further in his analysis of gravity. In his examination of the orbits of the planets, he ...

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Inductor and inductance:types and applications

What is Inductor and what does it do? When a length of wire is formed into a coil,it becomes a basic inductor. The term coil and inductor are used interchangeably.Current through the coil produced an electromagnetic field, as illustrated. The magnetic lines of force around each loop (turn) in the winding of the coil effectively add to the lines of ...

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Vernier caliper least count formula

Vernier caliper is an instrument used to measure the length,diameter,radius etc.It can measure up to 1/10 of mm (or 0.1 mm 0.01 cm) which is called least count of V.C .Its is used by the lathe mechanic for making metallic cylinders of different sizes. There are two scales of V.C Vernier scale Main scale Main scale is graduated is centimeter ...

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