1 Experiment 13 Series Parallel Circuits 1. In a series circuit, current is the same in all series components 2. In a parallel circuit, voltages across parallel components are equal. 3. The beginning point in analyzing a series parallel circuit is to determine which components are in series and which are in parallel Let’s apply these concepts to Figure 13-1 on the next page 1. In a series circuit, current is the same in all series components a. Therefore, the current through: i. R11, R7 and R3 is the same ii. R6 and R5 is the same 2. In a parallel circuit, voltages across parallel components are equal. a. Therefore, the voltage across: i. R1 and R2 is the same ii. R4 and R5 + R6 is the same iii. R8, R9, and R10 is the same 3. The beginning point in analyzing a series parallel circuit is to determine which components are in series and which are in parallel2 The key to analyzing this circuit is to simplify to a series circuit Reduce R8, R9 and R10 to one Resistor (parallel resistance formula). The Resistance is _______________ Reduce R1 and R2 to one Resistor (parallel resistance formula). The resistance is _______________ Reduce R4 and R5 + R6 to one Resistor (Parallel resistance formula). The Resistance is _______________ A R24.7kR32.2kR43.9kR62.7kR71.5kR85.6kR912kR1010kR111.0kR5820V140 V ABCDEFGGNDR13.3kR8, R9 and R10 are in parallel. The equivalent R is in series with R11 and R7. R1 & R2 are in parallel. The equivalent R is in series with R3 R4 is in parallel with R5 and R6. The equivalent R is in series with R3 and R2 Figure 13-13 What is the total resistance of the circuit?_______________ What is the series current for the simplified circuit?____________________ This would be the current that flows through R3, R7 and R11 Use ohms law 40volts/(Total R) The next step is to calculate the voltage drop across each component is the simplified circuit above. Uses Ohms law (I XR), to determine the voltage drop across the 5 components. If you add together the voltage drops across the 5 components, they should add up to 40 volts. Using Ohms Law calculate the values in Table 13-1 Component Calculated Voltage Current Calculation Measured Voltage using MultiSim Measured Current using MultiSim R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 Table 13-1 Download Experiment #13 from http://facweb.northseattle.edu/tfiegenb/EET160/MultiSim/additional_labs/ Open MultiSim Run Experiment 13 to measure values for table 13-1. _____________________________________ Questions below pertain to Figure 13-1: 1. The total circuit current will flow through which of the following resistors? a. R11, R7 and R3 b. R1, R2, and R3 c. R4, R5 and R6 d. R9, R4 and R24 2. The Sum of the currents through R1 and R2 is _________ma. 3. T F The same value of current flows through resistors R11 and R5. 4. T F The voltage drop across R4 is equal to the sum of the voltage drops across R5 and R6. 5. Circle the component voltage drops that could be added together to equal the supply voltage? R1R2 R3 R4 R5R6 R7 R8R9R10 R11 6. The current entering point C in Figure 13-1 equal to a. The sum of the currents through R3 and R7 b. The sum of the currents through R5 and R4 7. The current entering point D is equal to A a. The total circuit current b. The current that flows through R8 8. If resistor R11 were to open, the total circuit current would______ a. Increase to a very large value b. Remain the same c. Decrease to zero 9. If resistor R8 were to open, the total circuit resistance would______ a. Increase b. Decrease c. Remain the same 10. If resistor R1 were to open, the total circuit current would_______ a. Increase b. Decrease c. Remain the same 11. If resistor R7 increased to 15K, the voltage across R7 would_______ a. Increase b. Decrease c. Remain the same 12. If resistor R4 were to short, the voltage across R5 and R6 would________ a. Increase to equal the applied voltage b. Decrease to zero volts5 c. Remain the same value 13. If resistor R4 were to open. The voltage across R5 and R6 would ________ a. Increase b. Decrease c. Remain the same 14. The voltage at point D with respect to point A would measure the voltage drops across ______ a. Resistors R7 and R11 b. Resistors R6, R3 and R2 c. Resistors R4, R3 and R2 15. The voltage at point F with respect to the voltage at point B will be a. Positive b.