RL and RC ELECTRICAL CIRCUIT, Lecture notes of Physics

Download RL and RC ELECTRICAL CIRCUIT and more Lecture notes Physics in PDF only on Docsity! Laboratory Experiment No. 2 Series RLC Circuits I. DISCUSSION Resistance and impedance both represent opposition to the flow of the alternating current. Both are measured in terms of the same unit, the ohm. To determine the magnitude of the total impedance, get the sum of the impedance of each of the elements in series. As long as all the necessary calculations are carried out by vector algebra, use the two relationships studied earlier under DC circuits. The total impedance may not always increase with the addition of another element in series. Capacitive reactance could cancel out inductive reactance and vice versa. An extreme case would have the capacitive reactance completely cancelling out the inductive reactance. This results in resonance high voltages and current could result. II. OBJECTIVES The activity aims to: 1. Determine the resistance, inductance and capacitance by a voltage and current measurements. 2. Compare measured and calculated voltages and current for a series RLC circuit. 3. Determine the impedance of a given circuit to compare the measure value to calculated value of a given circuit. III. MATERIALS  100 w Lamp  5 uf Capacitor  2.5372 H Inductor  AC voltmeter  AC ammeter  AC supply  Multisim IV. PROCEDURE A. RLC Circuit a. Build the circuit given in figure 1 on Multisim. Figure 1 b. Measure the total current and the current across the lamp, across 2.5372 H inductor and across the 5uF capacitor. To measure the total current, refer to figure 2a. Record the current reading at table 1. Repeat the steps for the current lamp, 2.5372 H inductor and 5uF capacitor. Refer to figure 2b, 2c and 2d. Figure 2A Figure 2B e. Compute the magnitude and phase angle of the impedance using the equation Z’ = R –jXc + jXl, where Xl = 2πfL and Xc = 1/2πfC. Use the 4 uF for the value of and 2.5372 H inductor for the value of L. f. Compute the percent difference between the measure and the computed value of the impedance. Table 1: Simulation and Computation Result of Voltage of Series RLC Circuit Voltage (V) R L C Total Workbench Computation % Difference Table 2: Simulation and Computation Result of Current of Series RLC Circuit Current (A) R L C Total Workbench Computation % Difference V. ANALYSIS A. Questions a. Do the workbench and computational values of voltages and currents agree? b. Give possible reasons for any discrepancies. VI. CONCLUSION VII. APPLICATION A. Circuit Design a. Design a series RLC circuit which is connected to 220 V , 50 cycles, having a 100W, capacitor C and inductor L. The total impedance is 609.8121 ohms and the capacitive reactance is 530.5165 ohms. Find the value of R, L and C B. Problems a. Under what conditions could the total impedance of two impedances in series be less than that of either one by itself? b. Given the magnitude of two impedances in series, why can’t the total impedance of these two impedance is series be calculated