1. University Physics: Waves and Electricity Ch27. Circuit Theory Lecture 11 Dr.-Ing. Erwin Sitompul http://zitompul.wordpress.com

2. 11/2 January–April 2010University Physics: Wave and Electricity Homework IX (IT) (a)Find the equivalent resistance between points a and b in the circuit diagram below. (b)Calculate the current in each resistor if a potential difference of 34 V is applied between points a and b.

3. 11/3 January–April 2010University Physics: Wave and Electricity Solution of Homework IX (IT) (a) (b) ≡

4. 11/4 January–April 2010University Physics: Wave and Electricity Solution of Homework IX (IT) ≡ cd cd

5. 11/5 January–April 2010University Physics: Wave and Electricity Example: Single-Loop Circuit For the circuit shown, determine V ab. i a  a, cw a  b, ccw Assume a current direction Perform the calculation i > 0 means that the current flows in the assumed direction i < 0 means that the current flows in opposite direction Try again for i assumed to be ccw

6. 11/6 January–April 2010University Physics: Wave and Electricity Voltage Divider and Current Divider Voltage DividerCurrent Divider

7. 11/7 January–April 2010University Physics: Wave and Electricity R eq of Two Resistance in Parallel

8. 11/8 January–April 2010University Physics: Wave and Electricity Example: Finding Voltage and Current For this circuit, determine i 1, i 2, V 1, and V 2. ≡

9. 11/9 January–April 2010University Physics: Wave and Electricity Example: Two-Loop Circuit 1 2 If E 1 = 20 V, determine E 2 and E 3. Loop 1, cw Loop 2, cwOuter Loop, ccw

10. 11/10 January–April 2010University Physics: Wave and Electricity Multiloop Circuits  Junction Rule The sum of the currents entering any junction must be equal to the sum of the currents leaving that junction Remember again Loop Rule, Resistance Rule, and Emf Rule  Our basic tools for solving complex circuits are the loop rule and the junction rule. Junction Rule, at d Loop Rule, left-hand loop, b  b, ccw Loop Rule, right-hand loop, b  b, ccw Afterward, find the unknowns from these three equations..........(1)......(2)......(3)

11. 11/11 January–April 2010University Physics: Wave and Electricity Example: Multiloop Circuits The value of the elements in the following circuits are: E 1 = 3 V, E 2 = 6 V, R 1 = 2 Ω, R 2 = 4 Ω Find the magnitude and direction of the current in each of the branches. Junction Rule, at a Loop Rule, left-hand loop, a  a, ccw Loop Rule, right-hand loop, a  a, cw..........(1)...(2)...(3)

12. 11/12 January–April 2010University Physics: Wave and Electricity Example: Multiloop Circuits.......(1)...(2)...(3) Insert (1) into (3),...(4) Option A: Elimination Method Option B: Substitution Method From (2) Insert (5) into (4)........(5)

13. 11/13 January–April 2010University Physics: Wave and Electricity Homework X (IT) For the circuit depicted below, determine the currents (i 1, i 2, i 3 ) and the potential difference across the resistors (V 1, V 2, V 3 ).