1. Resistors come in all shapes and sizes…. Resistors – inhibit (or resist) flow of charges. Current - Net flow of charge Different sizes mean Different values of resistance Different amount of electrical power dissipated as heat

2. Clicker Question #1 Which of these diagrams indicate the largest net current? E E) The current is the same in all of the above.

3. Clicker Question #2 Which of these diagrams indicate a current going from left to right? E E) A and D

4. Microscopic model: 1) electric field accelerates charge 2) collisions with obstacles scatters charges into another (random) direction. (3) electric field accelerates charge. NET results is slow drifting motion of charge in direction of acceleration.

6. Clicker Question #3 What is the equivalent resistance of the network below? E A)2.95 Ω B)11.7 Ω C)35 Ω D)42 Ω E)Impossible to tell. Resistors not in series or parallel

7. Clicker Question #4 Given that the equivalent resistance is 11.7 Ω, how much power is dissipated by the 5 Ω resistor if Vab=10 volts? E A)Exactly Zero B)3.7 Watts C)8.5 Watts D)11.7 Watts E)20 Watts

9. Kirchhoff’s loop laws: NET flow into a junction is zero. For THIS example

10. Clicker Question #5 What is correct junction equation for the following junction? A) B) C) D) E) None of the above A B C

11. Clicker Question #6 For the given ASSUMED directions of the currents, what is the loop equation for the TOP loop going clockwise around the loop? A) B) C) D) E) None of the above A B C