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## Electro Magnetic Fields

### Preamble:

Electromagnetic fields square measure the pre-requisite for many of the topics within the gamut of applied science. The study of this subject permits students to grasp and interpret the development pertinent to applied science mistreatment microscopic quantities like electrical and field intensities, scalar and vector potentials.

#### Learning objectives:

• to review the assembly of electrical field and potentials because of completely different configurations of static charges.

• to review the properties of conductors and dielectrics, calculate the capacitance of assorted configurations and perceive the conception of physical phenomenon and convection current densities.

• to review the magnetic fields made by currents in numerous configurations, application of ampere’s law and also the Maxwell’s second and third equations.

• to review the attraction and torsion through Lorentz force equation in field setting like conductors and different current loops.

• To develop the conception of self and mutual inductances and also the energy hold on.

• to review time variable and Maxwell’s equations in numerous forms and Maxwell’s fourth equation for the evoked e.m.f.

#### UNIT – I

statics: Electrostatic Fields – Coulomb’s Law – field Intensity (EFI) – EFI because of a line Associate in Nursingd a surface charge – Work tired moving some extent charge in an electric field – electrical phenomenon – Properties of potential perform – Potential gradient – Guass’s law –– Maxwell’s 1st law, div( D )=ρv Laplace’s and Poison’s equations and answer of Laplace’s equation in one variable.

#### UNIT – II

Conductors – insulators and Capacitance: dipole – moment – potential and EFI because of an electrical dipole – torsion on an electrical dipole in an electrical field – Behaviour of conductors in an electrical field – Conductors and Insulators Polarization – Boundary conditions between physical phenomenon to Dielectric and insulator to dielectrics capacitance – capacitance of parallel plates, spherical and concentrical cables with composite dielectrics –Energy hold on and energy density in a very static field – Current density – physical phenomenon and Convection current densities – Ohm’s law in purpose kind – Equation of continuity

#### UNIT – III

magnetoelectric machine statics and Ampere’s Law: Static magnetic fields – Biot-Savart’s law – Oesterd’s experiment – field intensity (MFI) – MFI because of a straight current carrying filament – MFI because of circular, sq. and magnet current – Carrying wire – Relation between magnetic flux, magnetic concentration and MFI – Maxwell’s second Equation, div(B)=0 –Ampere’s circuital law and its applications viz. MFI because of Associate in Nursing infinite sheet of current and a protracted filament carrying conductor – purpose kind of Ampere’s circuital law –Field because of a circular loop, rectangular and sq. loops, Maxwell’s third equation, Curl (H)=J.

#### UNIT – IV

Force in fields: attraction – Moving charges in a very Magnetic field – Lorentz force equation – force on a current component in a very field – Force on a straight and a protracted current carrying conductor in a very field – Force between 2 straight long and parallel current carrying conductors – dipole and moment – a differential current loop as a dipole – torsion on a current loop placed in a very field.

#### UNIT – V

Self and coefficient: Self and Mutual inductance – determination of coefficient of self induction of a magnet and toroid and coefficient between a straight long wire and a sq. loop wire within the same plane – energy hold on and density in a very field.

#### UNIT – VI

Time variable Fields: Time variable fields – Faraday’s laws of magnetism induction – Its integral and purpose forms – Maxwell’s fourth equation, Curl (E)=-∂B/∂t – Statically and Dynamically evoked EMFs – straightforward issues -Modification of Maxwell’s equations for time variable fields – Displacement current – Poynting Theorem and Poynting vector.

#### Learning outcomes:

• to work out electrical fields and potentialsusing guass’s lawor resolution Laplace’s or Possion’s equations, for varied charge distributions.

• To Calculate and style capacitance, energy hold on in dielectrics.

• To Calculate the field intensity because of current, the applying of ampere’s law and also the Maxwell’s second and third equations.

• to work out the magnetic forces and torsion made by currents in field

• to work out self and mutual inductances and also the energy hold on within the field.

• To calculate evoked e.m.f., perceive the ideas of displacement current and Poynting vector.

#### Text Books:

one.“Engineering Electromagnetics” by William H. Hayt& John. A. Buck Mc. Graw-Hill corporations, 7th Editon.2006.

#### Reference Books:

one.“ Principles of Electro Magnetics” by Sadiku, Oxford Publications,4th edition a pair of.“Introduction to Electro Dynamics” by D J Griffiths, Prentice-Hall of Asian nation Pvt.Ltd, 2d edition