2011 년 10 월 28 일 제 7 장

 Electric charge  Electric force and Coulomb’s law  Electric Currents-Superconductivity  Electric circuits and Ohm’s law  Power and energy in electric currents  AC and DC

 Electric charge ◦ An inherent physical property of certain subatomic particles that is responsible for electrical and magnetic phenomena ◦ Charge is represented by q ◦ SI unit is the coulomb(C)

 Like charges repel, unlike charges attract

 The force acting on each of two charged objects is directly proportional to the net charges on the objects and inversely proportional to the square of the distance between them

 E-Paper  FET(Field Effect Transistor)

 집진기 ( electrostatic precipitator) Bluebird Co. Ltd.

 Copier( 복사기 )

 Conductor( 도체 ) ◦ a material allowing the flow of electric charge ◦ 일반적인 금속, 구리, 금, 은 등  Insulator( 부도체, 절연체 ) ◦ a substance that resists the flow of electric current ◦ 세라믹, 플라스틱, 석영, 공기, 등

 Current ◦ The rate of flow of electric charge. ◦ The amount of charge that flows by per second ◦ SI unit is the ampere(A or amp) ◦ Measured by ammeter

 Conductor ◦ Copper, silver, gold, aluminum  Insulator ◦ Plastic, rubber  Semiconductor ◦ Ge, Si,

 Voltage ◦ The work that a charged particle can do divided by the size of the charge ◦ The energy per unit charge given to charged particles by a power supply ◦ The SI unit is the volt(V), joule per coulomb

 The current in a conductor is equal to the voltage applied to it divided by its resistance

3V

 Series (current is the same)

 Parallel (voltage is the same)

12V Series & Parallel

120V 1875W

 Used for 3 minutes Energy? 120V 1875W

 AC(alternating current)  DC(direct current)