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Electricity & Megnetism

what is magnetic flux density?-definition & formula

Magnetic Flux (Φ) definition The group of force lines going from the north pole to the south pole of a magnet is called the magnetic flux, symbolized by Φ (the Greek letter phi). The number of lines of force in a magnetic field determines the value of the flux. The more lines of force, the greater the flux and the stronger the ...

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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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Difference between mutual and self induction

image of self induction of a coil

What is Mutual induction? “The process of inducing e.m.f in the secondary coil by changing the magnetic flux of the primary coil with the help of varying current through it is called mutual induction.” If two coils placed together ,then by changing current in one coil sets up a changing magnetic field in the other coil,so induced an e.m.f in ...

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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 differences between Gauss’s law and ampere’s law.

Analogies between Gauss’s law and Ampere’s law: Gauss’s law says the electric flux through a closed surface is proportional to the charge within the surface.Ampere’s law says the line integral of B.ds around a close path is proportional to the current that passes through that path. In Gauss’s law,the imaginary and arbitrary closed surface is taken enclosing a charge.In ampere’s ...

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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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Heating effects of electric current and joules law of heating

State Joule’s law of heating “The heat produced in a conductor is: (1) Directly proportion the square of current passing through the conductor,(H ∝ I²) keeping R and t constant; (2) Directly proportion to the resistance of the conductor (H ∝ R) keeping I and t constant;and (3)Directly proportional to the time of flow of current (H ∝ t) keeping I and R ...

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What are some applications of a step up and step down transformer?

Applications of a step up transformer For Transmission of electric power from power station to consumer,voltage is step up by using step up transformer.It minimizes the power loss in transmission line. Applications of a step down transformer Step down transformer decrease the voltage to a safe value at the end of the transmission line where the consumer of electric power ...

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