Series parallel circuit lab report conclusion

RL Series and Parallel Circuits

Experiment #1: Series RL Circuits

Objectives:

After p11erforming this experiment you will be able to:

1. Compute the inductive reactance of an inductor from voltage measurement in a series RL circuit

2. Draw the impedance and voltage phasor diagram for series RL circuit.

3. Measure the phase angle in a series circuit using either of the two methods.

Materials Needed:

Resistor: 10 KΩ - 1 Piece.

Inductor: 100 mH – 1 Piece.

Summary of Theory:

When a sine wave drives a linear series circuit, the phase relationship between the current and the voltage are determined by the components in the circuit. The current and voltage are always in phase across resistors. With capacitors, the current is always leading the voltage by 90o, but for inductors, the voltage always leads the current by 90o.

Figure 3-1-1(a) illustrates a series RL circuit. The graphical representation of the phasors for this circuit is shown in Figure 3-1-1(b) and (c) respectively. As in the series RC circuit, the total impedance is obtained by adding the resistance and inductive reactance using the algebra for complex numbers. In this example, the current is 1.0 mA, and the total impedance is 5 KΩ. The current is the same in all components of a series circuit, so the current is drawn as a reference in the direction of the x-axis. If the current is multiplied by the impedance phasors, the voltage phasors are obtained and shown in Figure 3-1-(c).

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Figure 3-1-1 (a)

Procedure:

In this experiment, you learn how to make measurement of the phases angle. Actual inductors may have enough resistance to affect the phase angle in the circuit. You will use a series resistor that is large compared to the inductor’s resistance to avoid this error.

1. Measure the actual resistance of a 10 KΩ resistor and the inductance of a 100 mH inductor. If the inductor cannot be measured, record the listed value. Record the measured values in Table 3-1-1.

2. Connect the circuit shown in Fig 3-1-2. Set the generator voltage with the circuit connected to 3.0 VPP at a frequency of 25 KHz. The generator should have no dc offset. Measure the generator voltage and frequency with oscilloscope as many meters cannot respond to 25 KHz frequency. Use peak-to-peak readings for all the voltage and current measurements in this experiment.