LVECS Basic Electrical Engineering (EE 419)

ME- 2112 October 27, 2022

Laboratory Activity No. 1
Series and Parallel Circuits
Voltage and Current Divider Rule

INTRODUCTION
While Multisim makes it possible to carry out this laboratory experiment, online classes
reduced the chances of actual learning. Multisim was used to simulate the circuits in this exercise.
It is a program with SPICE simulation, analysis, and printed circuit board (PCB) capabilities that
enable rapid design iteration and improved prototype performance. Smoothly transition from the
schematic to the layout to cut down on prototype iterations and save time. Instructors can use its
user-friendly interface to reinforce circuit theory and increase theory retention throughout the
engineering curriculum. This program may be used to calculate unknown voltage and current
values, but manual calculations are also required. This exercise contains two diagrams of series
and parallel circuits, which will be used in this simulation. However, the definitions and
distinctions between the terms "series" and "parallel" must first be established. Resistors are
chained together in a series circuit so that current can only flow in one direction. Through each
resistor, the current flows in the same direction. Resistors are arranged in a parallel circuit with
their heads and tails connected together. The current in a parallel circuit splits, with some moving
along each parallel branch before reuniting at the next junction. Each parallel resistor has the same
voltage across it.

Current Divider circuits have two or more parallel branches through which currents can flow,
but the voltage of all parallel circuit components is the same. The supplied current is divided into
numerous parallel channels in Current Divider Circuits, which are parallel circuits. All of the
components' terminals are connected to the same two end nodes in a parallel linked circuit. As a
result, the stream can travel through a variety of paths and branches. However, as they traverse
each component, the currents may have varying values. Two resistors connected in parallel is
another straightforward and easy-to-understand type of passive current divider network. We can
figure out how much of the total current flows through each parallel resistive branch using the
Current Divider Rule.

Fig. 1 Series Circuit Fig. 2 Parallel circuit

For a series circuit shown in figure 1, the voltage across resistors R 1, R2, and R3 can be
written as

This is the voltage divider rule (VDR)

For parallel circuit given in figure 2, the branch currents can be written in terms of the total
current as

This is termed as the current divider rule (CDR).

OBJECTIVES

1. To study the voltage current relationships of series and parallel circuits.

2. To verify the voltage divider and current divider rules.

MATERIALS

Multisim

CIRCUIT DIAGRAMS
PROCEDURE:

Start Multisim Live and construct a new circuit. Make the circuit in Figure 3. Select the DC
Voltage as the voltage source for the circuit to begin.

Rotate the diagonally positioned resistors (R2 and R6) horizontally while leaving resistor 4 alone
to duplicate the provided circuit. Set resistor 3 up so that it faces upward. Connecting them together
to form the circuit is the next step. Use the information provided to label it. Make the ground your
primary source of information.

However, connect the voltmeter first, then the voltage reference, in order to determine the voltage
of each resistor. Ensure that the provided direction is followed when connecting the ammeter to
each resistor's connecting lines (wires). Run a simulation for you to discover the unknown values.
Fill in the information in the provided table.

Repeat the preceding steps to create the circuit shown in Figure 4.

Figure 3. Simulation for Series-Parallel Circuit I

Figure 4. Simulation for Series-Parallel Circuit II

 SIMULATION
1. Build the circuit given in figure 3 on Multisim.
2. Connect voltmeters, ammeters (or multimeters) at appropriate positions to measure voltages
and currents shown in Table 1.
3. Disconnect the voltage source. Connect a multimeter and measure the total resistance and
record the value in Table 1. (Remember resistance is always measured without any source
connected to the circuit.)
4. Repeat steps 2 and 3 for the circuit given in figure 4 and record the values in Table 2

VI. DATA AND RESULTS

Table 1: Simulation and Experimental Results for Figure 3

Is I2 I3 I4 I5 I6 V2 V3 V4 V5 V6 Veq

Work 263.45 103.45 160.00 62.069 222.07 41.379 10.345 13.655 0 13.655 24V
Bench mA / mA / mA / mA / mA / mA / V V V
0.2634 0.1034 0.16 A 0.0620 0.2220 0.0413 24 V
5A 5A 69 A 7A 79
 Table 2: Simulation and Experimental Results for Figure 4
Is I2 I3 I4 I5 I6 V2 V3 V4 V5 V6 Veq

Work 118.35 99.969 18.377 18. 377 118.35 6.2481 4.8698 22.62 17.752 24V
Bench mA / mA / mA / 0. mA / 0. mA / / V 1.378 V 2V V
0.1183 0.0999 018377 018377 A 0 0.1183 3V
5A 69 A A 5A

QUESTIONS:

Refer to figure 3 and the results obtained in Table 1 and answer the following questions:

1. Are R4 and R6 in parallel or in series? Why? Refer to voltage current measurements for your

answer to justify.

 R4 and R6 are in parallel connection because as we can see in the Table 1, they have the
same results of voltage which is 13.655V satisfying the definition of parallel circuit wherein
the components share the same voltage. In addition to this, they are not series because I4
and I6 are not equal.

2. Are R3 and R4 in parallel or in series? Why? Justify with solution.

 As we can see in Table 1 showing the resulted measurements of current and voltages in
circuit I, R3 has a voltage of 24V and a current measured 0.016 A while R4 has a voltage
of 13.655 V and a current of 0.062069A. So that we will notice that two resistors have
different values of current as well as the voltage. Therefore, we can say that R3 and R4 are
not connected in series nor in parallel.
 • Solution
In parallel connection, it has an equal voltage. Therefore, V3 should be equal to V4.

V=IR
V3 = V4
(I3)(R3) = (I4)(R4)
(0.16)(150) = (0.062069)(220)

24V ≠ 13.655V

Therefore, R3 and R4 are not parallel.

In series connection, it has an equal current. Therefore, I3 should be equal to I4.

I=V/R
I3 = I4
(V3)/(R3) = (V4)/(R4)
(24)/(150) = (13.665)/(220)

0.16A ≠ 0.062069A

Therefore, R3 and R4 are not series.

3. Are Vs and R3 in parallel or in series? Why? Justify with solution.

 Vs and R3 are in parallel. As we can see Voltage Vs and V3 are same in magnitude which is

24 V. In the same way it is not in series because Is and I3 are not equal.

• Solution

In parallel connection, it has an equal voltages. Therefore, V3 should be equal to Vs which is

24V.
 V=IR

Vs = V3

24 V = (I3)(R3)

24 V = (0.16)(150)

24V =24 V

Therefore, Vs and R3 are parallel.

In series connection, it has an equal current. Therefore, Is should be equal to I3. Referring to the

table, we can get the value for Is.

I=V/R

Is = I3
0.26345 A = (V3)/(R3)

0.26345 A = (24)/(150)

0.26345A ≠ 0.16A

Therefore, Vs and R3 are not series.

4. Are Vs and R6 in series or in parallel? Why? Justify with solution.

 As we can see in the Figure 3, Vs and R6 are not connected in series nor parallel circuit
because Vs contains 24V and the current source is 0.26345A while in R6, the voltage is
13.655V and the current is 0.04137A. Moreover, it does not satisfy also the definition of
series circuit where it has only one path where the charge can flow making the current
similar to every part of the circuit.
 • Solution

In parallel connection, it has an equal voltage. Therefore, V6 should be equal to Vs which is 24V.

V=IR
Vs = V6
24V = (I6)(R6)
24V = (0.041379)(330)

24V ≠ 13.655V

Therefore, Vs and R6 are not parallel.

In series connection, it has an equal current. Therefore, Is should be equal to I6. Referring again to
the table, we can get the value for Is.

I=V/R
Is = I6
0.26345A = (V6)/(R6)
0.26345A = (13.665)/(330)
0.26345A ≠ 0.41409A

Therefore, Vs and R6 are not series.

5. Are Vs and Req in parallel or in series? Why? Justify with solution.

 When they provide the same voltage value, the voltage source and equivalent resistance are
in parallel. Although it cannot be termed a series because the current value is not the same.

• Solution
In order to be considered as parallel, the value of the voltage should be equal so Vs should have
the same value as the Veq.

𝐕𝐞𝐪 = 𝐕𝟐 + 𝐕𝟒 = 𝐕𝟐 + 𝐕𝟔 = 𝐕𝟑
Veq = 10.345 + 13.655 = 10.345 + 13.655 = 24V
 𝐕𝐞𝐪 = 𝟐𝟒𝐕
Therefore,
𝐕 = 𝐈𝐑
V𝑠 = V𝑒𝑞
𝟐𝟒 𝐕 = 𝟐𝟒 𝐕

Thus, voltage source and the equivalent resistance is parallel.

On the other hand, to be considered as a series, the current should have the same value, hence, Is
should be equal to Ieq .

𝐈 = 𝐕/𝐑
Is = Ieq
0.26345A = Veq/Req
0.26345 A = 24𝑉/382 𝑜ℎ𝑚𝑠
𝟎. 𝟐𝟔𝟑𝟒𝟓 𝐀 ≠ 𝟎. 𝟎𝟔𝟐𝟖𝟑 𝐀

Thus, voltage source and the equivalent resistance is not a series

6. Is VDR applicable for R3 and R4? Why? Justify your answer on the basis of theory given in

the introduction.

 VDR (Voltage Division Rule) is not applicable for R3 and R4 because this theory is only
applied in two resistors that are connected in series and since, R3 and R4 are not in series
or parallel, therefore, VDR cannot be used because it contradicts the theory.

7. Is CDR applicable for R4 and R6? Why? Justify your answer on the basis of theory given in

the introduction.

 For R4 and R6, CDR (Current Division Rule) is applicable because they are connected in
parallel. Voltages are same in parallel which can be explained by the value of V4 and V6.
8. Is the parallel combination of R4 and R6 in series or in parallel with R2? Why? Justify.

 The parallel combination of R4 and R6 can be thought of as a series with R2. Considering
current I2 is equal to the total of currents I4 and I6, it follows that the current in R2 is the
same as the current in the parallel combination of R4 and R6.
Refer to figure 4 and the results obtained in Table 2 and answer the following questions:

9. Are R4 and R6 in parallel or in series? Why? Refer to voltage current measurements for your

answer to justify.

 Resistor 4 and Resistor 6 cannot be considered as parallel nor series since it does not obtain
the same value of voltage nor current which is the fundamental rule of parallel and series
connection, respectively. As shown in the data above, the voltage of R4 is 1.3783V while
the current is 0.018377A. On the other hand, the voltage of R6 is 4.8698V while current is
0.11835A.

10. Are R3 and R4 in parallel or in series? Why? Justify with solution.

 R3 and R4 are connected in series. They have the same current flowing via both resistors.
The current in R3 and R4 is 0.018377A, according to the table. However, it cannot be
parallel since V3 is 24 volts and V4 is 4.8698 volts.

• Solution

In parallel connection, it has an equal voltages. Therefore, V3 should be equal to V4.

V=IR

V3 = V4

(I3)(R3) = (I4)(R4)

(0.018377)(75) = (0.018377)(265)
 1.378275V ≠ 4.869905V

Therefore, R3 and R4 are not parallel.

In series connection, it has an equal current. Therefore, I3 should be equal to I4.

I=V/R

I3 = I4

(V3)/(R3) = (V4)/(R4)

(1.3783)/(75) = (4.8698)/(265)

0.018377A = 0.018377A

Therefore, R3 and R4 are series.

11. Are Vs and R3 in parallel or in series? Why? Justify with solution.

 Vs and R3 are neither in series nor parallel. The voltage and current of the resistors are not
the same in the data above. The voltage source (Vs) is 24V and the current source is
0.11835A, but in R3, the voltage is 1.3783V and the current is 0.018377A.

• Solution

In parallel connection, it has an equal voltage. Therefore, V3 should be equal to Vs which is 24V.
We should get the value of V3 using the V = IR.

V=IR
Vs = V3
24V = (I3)(R3)
24V = (0.018377)(75)

24V ≠1.378275V
 Therefore, Vs and R3 are not parallel.

In series connection, it has an equal current. Therefore, Is should be equal to I3. Referring to the
table, we can get the value for Is.
I=V/R
Is = I3
0.11835A = (V3)/(R3)
0.11835A = (1.3783)/(75)

0.11835A ≠ 0.018377A

Therefore, Vs and R3 are not series.

12. Are Vs and R6 in series or in parallel? Why? Justify with solution.

 Vs and R6 are connected in series. They have the same current on both resistors in the
aforementioned data. The voltage in Vs is 24V and the current is 0.11835A, while the
voltage in R6 is 17.752V and the current is 0.018377A.

• Solution

In parallel connection, it has an equal voltages. Therefore, V6 should be equal to Vs which is

24V.We should get the value of V6 using the V = IR

V=IR

Vs = V6

24V = (I6)(R6)

24V = (0.11835)(150)

24V ≠ 17.7525V
 Therefore, Vs and R6 are not parallel.
In series connection, it has an equal current. Therefore, Is should be equal to I6. Referring to the

table, we can get the value for Is.

I=V/R

Is = I6

0.11835A = (V6)/(R6)

0.11835A = (17.752)/(150)

0.11835A = 0.11835A

Therefore, Vs and R6 are series.

13. Are Vs and Req in parallel or in series? Why? Justify with solution.

 When they provide the same voltage value, the voltage source and equivalent resistance are
connected in parallel. However, it cannot be termed a series because the current values are
not the same.

• Solution

In order to be considered as parallel, the value of the voltage should be equal so Vs should have
the same value as the Veq.

𝐕𝐞𝐪 = 𝐕𝟐 + 𝐕𝟔 = 𝐕𝟑 + 𝐕𝟓
Veq = 6.248 + 17.752 = 1.3783 + 22.622
𝐕𝐞𝐪 = 𝟐𝟒𝐕
Therefore,
𝐕 = 𝐈𝐑
V𝑠 = V𝑒𝑞
𝟐𝟒𝐕 = 𝟐𝟒𝐕

Thus, voltage source and the equivalent resistance is parallel.

On the other hand, to be considered as a series, the current should have the same value, hence, Is
should be equal to Ieq .
𝐈 = 𝐕/𝐑
Is = Ieq
0.11835A = Veq/Req
0.11835A = 24𝑉/384.1176 𝑜ℎ𝑚𝑠
𝟎. 𝟏𝟏𝟖𝟑𝟓𝐀 ≠ 𝟎. 𝟎𝟔𝟐𝟒𝟖𝐀

Thus, voltage source and the equivalent resistance is not a series.

14. Is VDR applicable for R3 and R4? Why? Justify your answer on the basis of theory given

in the introduction.

 VDR (Voltage Division Rule) applies to R3 and R4 since they are connected in series and
have the same current, which satisfies the rule. According to the lesson, we may apply the
voltage divider rule when a voltage source is connected to a series circuit and two series
resistances are connected to the path.

15. Is CDR applicable for R4 and R6? Why? Justify your answer on the basis of theory given

in the introduction.

 R4 and R6 are neither in series nor parallel, thus the CDR (Current Division Rule) applies.
When there are several parallel pathways in a circuit, we use the current division rule,
according to theory.

16. Is the parallel combination of R4 and R6 in series or in parallel with R2? Why? Justify with

solution.

 R4 and R6 are neither in series nor parallel. According to the data above, the R2 has a
voltage of 6.2481V and a current of 0.099969A. By equating R4 and R6, we discovered
 that they are neither series nor parallel. As a result, we may conclude that R4 and R6 are
neither in series nor parallel with R2.

• Solution

In parallel connection, it has an equal voltages. Therefore, V4 should be equal to V6.

V=IR

V4 = V6

(I4)(R4) = (I6)(R6)

(0.018377)(265) = (0.11835)(150)

4.869905V ≠ 17.7525V

Therefore, R4 and R6 are not parallel.

In series connection, it has an equal current. Therefore, I4 should be equal to I6.

I=V/R

I4 = I6

(V4)/(R4)= (V6)/(R6)

(4.8698)/(265) = (17.752)/(150)

0.018377A ≠ 0.11835A

Therefore, I4 and I6 are not series.

CONCLUSION

Students can easily comprehend the series and parallel operations that can be used to
obtain the appropriate data for the circuits in this activity with the help of Multisim. Using
Multisim, the circuit diagrams were created to examine the connectivity of each component in a
way that was easy to understand. We were able to better comprehend and identify such circuit
layouts thanks to this laboratory experiment. Additionally, I discovered that voltage and current
are linked in series and parallel circuits. Additionally, it provides the appropriate data for the
analyzed circuits. Using the simulation, the shown diagram, and the questions in this exercise, it is
possible to answer the questions in this activity because of the data. We learn a lot about parallel
and series circuits from it.

In conclusion, we can quickly and precisely determine whether a connection is in series

or parallel by employing Multisim electronics. By comprehending and resolving the measurement
and relationship that a current and voltage have with their corresponding resistors in each
connection, mathematical rules like the Voltage Divider Rule and the Current Divider Rule assist
us in determining the type of circuit. This makes the process more scientific and reliable. In
addition, this activity demonstrated that humans will be able to compute even in the absence of
technology or software that can effectively calculate the required measurements and data. In
addition, this activity demonstrated that, even in the absence of any technology or software that
makes it simple to compute the necessary measurements and data, we will still be able to compute
and identify the type of components in a circuit by applying some rules or even by simply observing
how resistors are plotted and connected.