ES lab report 3.docx - 1.0 Introduction The purpose of this...

1.0 Introduction
The purpose of this laboratory session was to introduce basic measurement and analysis
methods for AC circuits. This laboratory session analysed voltages in series resistor, capacitor
and inductor with the use of test equipments like:
 Digital Oscilloscope
 Function Generator
2.0 Summary of Results
The Phasor Diagram obtained from all the circuits in experiment shows that the measured
values for peak to peak voltages are reliable as the sum of voltage rise and drop is zero.
However a significant difference in values for the calculated and measured values can be
noticed in experiment 3, which mainly occurred due to the resistance of the inductor not
being taken in to account for the measurement of the calculated values. When the frequency
of the circuit in figure 1.1 was increased, the peak to peak voltage for the capacitance was
seen to decrease and phase angle was seen to be increasing. On the other hand when the
frequency of circuit in figure 1.3 was increased, the peak to peak voltage for the inductor was
increasing and the phase angle decreasing.
3.0 Circuits
Figure 1.1

Figure 1.2
Figure 1.3

4.0 Results
4.1 Sine Wave Measurements
℮
1
= E
m1
sin t ± ø= 9.5sin (11000-π/6) volts Ѡ
Table 1: Measurements of Sine wave
Quantity Measured Calculated Percentage
Difference (%)
℮
1(0.11ms)
(V) ------------ 6.021 ------------
Frequency (kHz) 1.741 1.751 0.57
Period (μs) 575 571 0.70
E
P
(V) 9.6 9.5 1.05
E
P/P
(V) 19.2 19 1.05
E
RMS
(V) 6.66 6.72 0.90
E
AV
(V) 6.84 6.05 12.26
Phase θ (Degrees) ------------- 60 ----------------
Table 2: Measurements of Sine wave using 17.5 kHz frequency
Quantity Measured Calculated Percentage
Difference (%)
Frequency (kHz) 17.52 17.50 0.11
Period (μs) 57.18 57.1 0.14
E
P
(V) 9.60 9.50 1.05
E
P/P
(V) 19.2 19.0 1.05
E
RMS
(V) 6.53 6.72 2.87
E
AV
(V) 4.88 6.05 21.41
4.2 Series RC Circuit
Resistor R
1
: 330 Ω
Capacitance C
1
: 0.15 μF
Refer to Figure 1.2 and 1.2
Table 3: Series RC Circuit using 5 kHz Frequency
Quantity Measured Values Theoretical
Calculated Values
Percentage
Difference (%)
Frequency (kHz) 4.992 5.0 0.16
Period (ms) 200.2 200 0.10
Input Voltage E
P/P
(V)
15.0 15.0 0.00
Volts
(V)
∆t
(μs)
Angle
(Degrees
)
Volts
(V)
Angles
(Degrees
)
Volts (V)
V
C
(peak to peak) 8.20 30 -54.0 8.11 -57.3 ----------------
V
R
(peak to peak) 12.4 19 34.2 12.62 32.7 ----------------

Table 4: Series RC Circuit using 2.5 kHz Frequency