Unit 2: Electromagnetic Quantities PDF

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Notice of Fair Use Copyright Disclaimer Under Section 185.1 of the IP Code of the Philippines - R.A. 8293: “The fair use of a copyrighted work for criticism, comment, news reporting, teaching including multiple copies for classroom use, scholarship, research, and similar purposes is not an infringement of copyright.”  Unit 2 ECE209: Electromagnetics An Overview of Electromagnetic Quantities: Parallelisms of Electric and Magnetic Quantities UNIT 2: Parallelisms of Electric and Magnetic Quantities 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Permittivity Permeability Charges Poles Fields Fields Flux Flux Force Force Capacitance Inductance Stored Voltage Induced Voltage EMF MMF Resistance Reluctance 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Permittivity Permeability ε = εr εo Unit is Farad per meter (F/m) μ = μr μo Unit is Henry per meter (H/m) εr : dielectric constant or relative permittivity of Note: 1 T-m/A = 1 H/m the material (Unit-less) εo = 8.8542 x 10–12 F/m μr : relative permeability of the material (Unit- less) εo = 8.8542 pF/m μo = 1.2566 x 10–6 H/m μo = 1.2566 μH/m 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Charges Poles Positive & Negative North & South Can exist separately as One found in each magnet’s purely positive and purely end. Monopoles does not negative charge exists. Like – Repel, Unlike - Attract Like – Repel, Unlike - Attract 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Fields Fields Actual Field Actual Field E-Field from by Gauss’ and Coulomb’s Laws H-Field : E = Qin/(εA) = Fe/Q = kQ/r2 H Units: N/C or V/m Unit : A/m Flux Density Flux Density D-Field B-Field D = εE = Qin/A B= μH Units: C/m2 Units: T : Tesla (MKS) ; G : Gauss (CGS) 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Flux Flux E-Flux H-Flux ΦE = EA cos θ ΦH = HA cos θ Unit: V-m Unit: A-m for MKS and Oersted (Oe) for CGS D-Flux B-Flux ΦD = ε ΦE = DA cos θ ΦB = μ ΦH = BA cos θ Unit: Coulombs (C) Unit: Weber (Wb) for MKS and Maxwell (Mx) for CGS (F/m)(V-m) = F-V = (C/V)(V) = C 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Force Force 1. From Coulomb’s Law B-Field Force FE = k|Q1Q2|/r2 1. Moving charge (Q) moving with velocity (v): 2. From Electric Field FB = QBv sin θ FE = EQ 2. Inside a conductor of length (l) and current (I) Unit: Newtons (N) FB = IlB Unit: Newtons (N) 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Electromotive Force (EMF) Magnetomotive Force (MMF) 1. From Faraday’s Law 1. Number of turns (N) and Current (I) in the coil: EMF = –N(dΦB/dt) MMF = Fm = NI 2. From Electric Field Unit: Ampere-Turns (A-t) or Gilberts (Gi) Where: 1 A-t = 1.2566 Gi V = Er Unit: Volts (V) 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Resistance (R) Reluctance (Rm) 1. From material’s physical properties: 1. From material’s physical properties: R = (ρl)/A Rm = l/(μA) 2. From Electric Circuits and Ohm’s Law: 2. From magnetic circuit R = EMF/I = V/I Rm = MMF/ΦB = (NI)/ΦB Unit: Ohms (Ω) Unit: Rels = Ampere-Turns per Weber (A-t/Wb) 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Capacitance (C) Inductance (L) 1. From material’s physical properties: 1. From material’s physical properties: C = (εA)/r L = (μAN2) / l 2. From Charge (Q) and Voltage (V): Unit: Henry (H) C = Q/V Unit: Farads (F) 2.1. Parallelisms of Electric and Magnetic Quantities Electric Magnetic Stored Energy Stored Energy in Capacitor (UC) Inductor (UL) From Capacitance (C) and Voltage (V): From Inductance (L) and Current (I): UC =½ CV2 UL = ½ LI2 Unit: Joules(J) Unit: Joules (J)