ECE 1270: Introduction to Electric Circuits Lecture 2: Ohm's Law Chapter 2 Circuit Elements

Voltage and Current Sources An Ideal Voltage Source An Ideal Current Source An ideal voltage source will provide a constant voltage across its terminals regardless of the current flowing into those terminals An ideal current source will provide a constant current flowing through its terminals regardless of the voltage across those terminals

Voltage and Current Sources ____ Controlled Voltage Source ____ Controlled Voltage Source ____ Controlled Current Source ____ Controlled Current Source

Example 2.1: Valid or Invalid? (b) (a) Valid: a,b,e, Invalid: c,d (c) (e) (d)

Example 2.2: Valid or Invalid? (c) Valid: b,c Invalid: a,d (b) (d)

AP 2.1

Ohm's Law R =Electrical Resistance [Ω] v = Voltage [V] i = Current [A] Resistance is created by the atoms in a material through which the electrons are moving

Example 2.4: Circuit Model of a Flashlight Lamp Coil Wire Metal Case Switch

P2.9, P2.11