1. Charge, Electric Field and Potential Eung Je Woo Department of Biomedical Engineering Impedance Imaging Research Center (IIRC) Kyung Hee University Korea ejwoo@khu.ac.kr

2. IIRC, Kyung Hee Univ.February, 2015 2 Fundamental Quantity Length (dimension or size) in meter (m) Time (sequence or duration or interval) in second (s) Mass in kilogram (kg) Charge in coulomb (C) Temperature in kelvin (K) Amount of substance in mole (mol) Luminous intensity in candela (cd) Mechanics Electromagnetics Optics Thermodynamics Chemistry

3. IIRC, Kyung Hee Univ.February, 2015 3 Charged Particle and Charge Density Free electron and hole are mobile Unbounded ion and molecule are mobile Bounded atom and molecule are immobile but may vibrate Polar molecule has no net charge but dipole moment and may rotate Mass Charge Size Position

4. IIRC, Kyung Hee Univ.February, 2015 4 Electric Field Space with nothing Space with a single charged particle Space with two charged particles Space with multiple charged particles Space with a charge density distribution Q x y z 0 QrQr r

5. IIRC, Kyung Hee Univ.February, 2015 5 Potential or Voltage Space with electric field E(r) Put a point charge at r1 from the infinity (a reference point) Move the point charge from r1 to r2 QrQr r1r1 E(r) QrQr r2r2

6. EOD