Lab Report Title:
SRIES D.C CIRCUITS
General Information:
Collage Faculty of Aviation Science
Instructor Name Mohummed abo khdair Instructor Email m.abukhdair@aau.edu.jo
Department Aircraft Electronics (Avionics)
Student Name Ahmad Yu
Student ID 202310084
Table of Content
Page Number Content
1 General Information, Abstract, Introduction
2 Introduction, Materials & Equipment, Procedure
3 Collected Data, Results, Concusion
Abstract:
This experiment investigates the fundamental principles of series DC circuits, focusing on Ohm’s Law
and Kirchhoff’s Voltage Law (KVL). Three resistors (R1=5400Ω, R2=8000 , R3=100 ) were connected
in series to a 9.3V DC power supply. Theoretical calculations for total resistance, current, and voltage
drops were compared with measured values using a digital multimeter (DMM). Results confirmed that
current remains constant in a series circuit, while voltage divides proportionally across resistors. Minor
deviations (<5%) in voltage measurements were attributed to resistor tolerances and instrument error,
but KVL was validated with a near-perfect match (9.3V). This experiment underscores the
predictability of series circuits and highlights practical considerations for real-world applications.
Introduction:
Direct Current (DC) series circuits are foundational in electrical engineering, where components are
connected end-to-end in a single path for current flow. This experiment explores two key principles:
1. Ohm’s Law (V=IR), which relates voltage, current, and resistance.
2. Kirchhoff’s Voltage Law (KVL), stating that the sum of voltage drops in a closed loop equals the
source voltage.
1
Using resistors of known values (5400Ω, 8000Ω, and 100 Ω), we constructed a series circuit powered
by a 9.3V DC source. Theoretical predictions for total resistance (RT=13,500Ω), circuit current
(I≈0.689mA), and individual voltage drops were derived. Practical measurements were then taken
using a DMM to verify these calculations.
Objectives:
• Validate Ohm’s Law and KVL in a series DC circuit.
• Analyze discrepancies between theoretical and measured values.
• Understand the impact of component tolerances on circuit behavior.
This experiment not only reinforces theoretical concepts but also develops essential skills in circuit
assembly, instrumentation, and error analysis—critical for advanced studies in avionics and electronics.
Materials & Equipment
1. ETW-3600 Analog Trainer
2. Resistors
3. jumper wires
4. Digital multi-Meter
Procedure
1. Circuit Assembly:
- Connected R1, R2, and R3 in series on the breadboard.
- Attached the positive terminal of the power supply to R1 and
the negative terminal to R3.
2. Current Measurement:
- Set DMM to DC current (mA) mode.
- Opened the circuit near R3 and inserted the DMM in series.
- Recorded the current.
3. Voltage Measurements:
- Set DMM to DC voltage (V) mode.
- Measured voltage drops across each resistor (VR1,VR2,VR3).
4. Verification of KVL:
o Summed the voltage drops and compared them to the
source voltage.
2
Calculations:
Theoretical Values:
1. Total Resistance (RT):
RT=R1+R2+R3=5400+8000+100=13,500Ω
2. Circuit Current (I):
𝑽 𝟗. 𝟑
𝑰= = ≈ 𝟎. 𝟔𝟖𝟗 𝒎𝑨
𝑹𝒕 𝟏𝟑. 𝟓𝟎𝟎
3. Voltage Drops:
𝑽𝑹𝟏 = 𝑰 × 𝑹𝟏 = 𝟎. 𝟔𝟖𝟗𝒎𝑨 × 𝟓𝟒𝟎𝟎𝜴 ≈ 𝟑. 𝟕𝟐
𝑽𝑹𝟐 = 𝑰 × 𝑹𝟐 = 𝟎. 𝟔𝟖𝟗𝒎𝑨 × 𝟖𝟎𝟎𝟎𝜴 ≈ 𝟓. 𝟓𝟏
𝑽𝑹𝟑 = 𝑰 × 𝑹𝟑 = 𝟎. 𝟔𝟖𝟗𝒎𝑨 × 𝟏𝟎𝟎𝜴 ≈ 𝟎. 𝟎𝟔𝟗
4. KVL Verification:
VR1+VR2+VR3= 3.72 + 5.51 + 0.069 ≈ 9.3V
Collected Data
Parameter Theoretical Value Measured Value Deviation (%)
Total Resistance (RT) 13500 𝜴 - -
Current (I) 0.689mA 0.78mA
VR1 3.72V 3.78V
VR2 5.51V 5.48V
VR3 0.069V 0.066V
Results & Discussion
Key Observations:
• The measured current should be close to 0.689 mA (if resistors are exact).
• The sum of voltage drops should equal 9.3V, confirming KVL.
• Deviations may occur due to:
Resistor tolerance (±5% or more).
DMM measurement errors.
Loose breadboard connections.
Conclusion
• The experiment confirmed Ohm’s Law (V=IR) and KVL in a series DC circuit.
• Minor deviations between theoretical and measured values were due to resistor tolerances and
measurement errors.
