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EE2030: Electromagnetics (I). Text Book: - Sadiku, Elements of Electromagnetics, Oxford University. References: - William Hayt, Engineering Electromagnetics, Tata McGraw Hill. Part 1: Vector Analysis. Associative Law:. Distributive Law:. Vector Addition.
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EE2030: Electromagnetics (I) Text Book: - Sadiku, Elements of Electromagnetics, Oxford University References: - William Hayt, Engineering Electromagnetics, Tata McGraw Hill
Part 1: Vector Analysis
Associative Law: Distributive Law: Vector Addition
Vector Representation in Terms of Orthogonal Rectangular Components
Vector Expressions in Rectangular Coordinates General Vector, B: Magnitude of B: Unit Vector in the Direction of B:
We are accustomed to thinking of a specific vector: A vector field is a function defined in space that has magnitude and direction at all points: where r = (x,y,z) Vector Field
Commutative Law: The Dot Product
B • a gives the component of B in the horizontal direction (B • a)a gives the vector component of B in the horizontal direction Vector Projections Using the Dot Product
Given Find where we have used: Note also: Operational Use of the Dot Product
Begin with: where Therefore: Or… Operational Definition of the Cross Product in Rectangular Coordinates
dV = dddz Differential Volume in Cylindrical Coordinates
Dot Products of Unit Vectors in Cylindrical and Rectangular Coordinate Systems
Example Transform the vector, into cylindrical coordinates: Start with: Then:
Example: cont. Finally:
Point P has coordinates Specified by P(r) Spherical Coordinates
Differential Volume in Spherical Coordinates dV = r2sindrdd
Dot Products of Unit Vectors in the Spherical and Rectangular Coordinate Systems
Transform the field, , into spherical coordinates and components Example: Vector Component Transformation
Constant coordinate surfaces- Cartesian system • If we keep one of the coordinate variables constant and allow the • other two to vary, constant coordinate surfaces are generated in rectangular, cylindrical and spherical coordinate systems. • We can have infinite planes: • X=constant, • Y=constant, • Z=constant • These surfaces are perpendicular to x, y and z axes respectively.
Constant coordinate surfaces- cylindrical system • Orthogonal surfaces in cylindrical coordinate system can be generated as • ρ=constnt • Φ=constant • z=constant • ρ=constant is a circular cylinder, • Φ=constant is a semi infinite plane with its edge along z axis • z=constant is an infinite plane as in the • rectangular system.
Constant coordinate surfaces- Spherical system • Orthogonal surfaces in spherical coordinate system can be generated as • r=constant • θ=constant • Φ=constant • r=constant is a sphere with its centre at the origin, • θ =constant is a circular cone with z axis as its axis and origin at the vertex, • Φ =constant is a semi infinite plane as in the cylindrical system.
Line integrals • Line integral is defined as any integral that is to be evaluated along a line. A line indicates a path along a curve in space.
DEL Operator • DEL Operator in cylindrical coordinates: • DEL Operator in spherical coordinates:
Gradient of a scalar field • The gradient of a scalar field V is a vector that represents the • magnitude and direction of the maximum space rate of increase of V. • For Cartesian Coordinates • For Cylindrical Coordinates • For Spherical Coordinates