Electromagnetism Lecture#11 Part (1) MUHAMMAD MATEEN YAQOOB THE UNIVERSITY OF LAHORE SARGODHA CAMPUS SERIES-PARALLEL CIRCUITS Identifying Series-Parallel Relationships Analysis of Series-Parallel Resistive Circuits MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE IDENTIFYING SERIES-PARALLEL RELATIONSHIPS A series-parallel circuit consists of combinations of both series and parallel current paths. It is important to be able to identify how the components in a circuit are arranged in terms of their series and parallel relationships. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE IDENTIFYING SERIES-PARALLEL RELATIONSHIPS MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE IDENTIFYING SERIES-PARALLEL RELATIONSHIPS MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Describe the total resistance between each pair of terminals in the following Figure. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE ANALYSIS OF SERIES-PARALLEL RESISTIVE CIRCUITS If you know Ohm's law, Kirchhoff's laws, the voltage-divider formula, and the current divider formula, and if you know how to apply these laws, you can solve most resistive circuit analysis problems. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Find the total resistance between the positive and negative terminals of the battery in the following Figure. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Find the current through R 2 and the current through R 3 in the following Figure. I 2 = (1.32K/2.2K)*9.48mA = 5.69 mA I 3 = (1.32K/3.3K)*9.48mA = 3.79 mA MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Determine the current through R4 in the following Figure. if Vs = 50 V. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE VOLTAGE DIVIDERS WITH RESISTIVE LOADS We have studied Voltage dividers in Series circuits. Now we see how resistive loads affect the operation of voltage-divider circuits. Effect of Load resistors Reduces resistance from Point A to ground So Voltage too More current is drawn from the source because the total resistance of the circuit is reduced. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE (a) Determine the unloaded output voltage of the voltage divider in the following Figure. (b) Find the loaded output voltages of the voltage divider in the following Figure for the following two values of load resistance: RL = 10 k and RL = 100 k. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE The R/2R Ladder Network A basic R/2R ladder network is shown in following Figure. The name comes from the relationship of the resistor values. R represents a common value, and one set of resistors has twice the value of the others. The R/2R ladder network is commonly used to scale down voltages to certain weighted values for digital-to- analog conversion. MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE The switches used in this illustration simulate the digital (two- level) inputs. One switch position is connected to ground (0 V), and the other position is connected to a positive voltage (V). MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Analysis of R/2R Ladder Network Switch SW4 is at the V position and the others are at ground MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Switch SW3 is at the V position and the others are at ground MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE Switch SW2 is at the V position and the others are at ground MATEEN YAQOOB DEPARTMENT OF COMPUTER SCIENCE