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Electricity & Megnetism

what is Difference between induced emf and induced current?

There are many ways to produced induced emf figure illustrated one of them. Consider a straight piece of wire of length l placed in the magnetic field of a permanent magnet. The wire is connected to a sensitive galvanometer. This forms a closed path or loop without any battery. In beginning when the loop  is at rest in the magnetic ...

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Maxwell’s equations:Derivation in integral and differential form

Maxwell equations

The 4 Maxwell equations The basic equations of electromagnetism which are collection of Gauss’s law for electricity ,Gauss’s law for magnetism ,Faraday’s law of electromagnetic induction and Ampere’s law for currents in conductors are called Maxwell’s equations. These equations are part of comprehensive and symmetrical theory of electromagnetism,which is essential to understand electromagnetic waves,optics,radio and TV transmission,microwave ovens and magnetically ...

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Resistance in series and parallel circuits

Combinations of resistance in electric circuit There are two possible combinations of resistance in electric circuits: Series combination Parallel combination Series combination In series combination,resistors are connected end to end and electric current has a single path through the circuit.This means that the current passing through each resistor is the same. The current is the same through all points in ...

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Inductance of a toroid formula derivation and examples

What is toroid? The solenoid bent into circular shape is called toroid. Inductance of a toroid derivation Consider a toroid having rectangular cross sectional area.The inner radius of the toroid is ‘a’ while outer radius is b.The number of turns of toroid is N.Let i be the current flowing through each turn of toroid. The magnetic field lines inside the ...

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chemical effects of electric current

Chemical effects of current Voltmeter or coulomb meter: The vessel in which electrolytes is carried out.It is also called electrolytic cell. Electrolyte: An ionic compound in aquas solution or molten state is called an electrolyte. Electrolysis: On passing current through an electrolyte,chemical changes occur in electrolyte and substances are liberated at the electrodes.This process is called electrolysis. Faraday’s laws: First ...

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coulomb’s and newton’s gravitational law: differences and similarities

Coulomb’s law Newton’s law of gravitation Comparison of Coulomb’s law and Newton’s law of gravitation The electrical force between two charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them:It is expressed The gravitational force between two masses is directly proportional to the product of their masses and inversely ...

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biot savart law:definition, examples, problems and applications

What is the definition of biot savart law? “The magnetic induction at any point produced by current element is directly proportional to the product of the current and the differential element and inversely proportional to the square of distance of the point from the differential element.” Formula of Biot Savart law [latex]\dB=\frac { { \mu  }_{ 0 } }{ 4\pi ...

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Discuss analogies and the differences between Coulomb’s law and the Biot- Savart’s law?

Similarities: Both the electric and magnetic field depends inversely on square of distance between the source and field point. Both electric field and magnetic field are proportional to the source strength namely charge and current element respectively. Both obey superposition principle. Differences: According to Coulomb’s law,the electrostatic force between two point charges is directly proportional to the product of their ...

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Can a transformer operate on DC?

A transformer cannot operate on a steady or unchanging dc voltage such as that of a battery.It requires a voltage which rises and falls.Since an ac voltage not only changes its magnitude but its direction as well,it is used to operate the transformers. However,a transformer will operate from dc voltage if this voltage also undergoes changes.Transformers used for audio amplifiers ...

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Eddy current testing principle

What is eddy current? A current induced in a conductor when subject to a varying magnetic field.Such currents are a source of energy dissipation (eddy current loss) in alternating current machinery.The reaction between the eddy currents in a moving conductor and the magnetic in which it is moving is such as to retard the motion.This property of eddy currents is ...

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