ELECTRIC FIELD AROUND A CONDUCTOR

DEPARTMENT OF ELECTRICAL AND
COMMUNICATIONS ENGINEERING
SEMESTER: 2. YEAR: 2025
Circuit THEORY
Circuit Theory Lab Experiment Lab # 1:
OHMS LAW
GROUP MEMBERS
ID NUMBERS
SIGNATURES
Paul AIPOS
24301597
Jethro AMBROSE
24301326
La;Zoe GORIE
24301408
Jordan KAMESO
23300610
Joy KOLIMA
24301097
Lab experiment done on: 1st of August 2025
Lab Instructor: Mr. Lolong Bonner Sign: ________________________

CIRCUIT THEORY EE223 LAB № 1
Ohms Law
Introduction:
Ohm's Law is a fundamental principle in electrical engineering and physics that describes the relationship
between voltage, current, and resistance in a conductor. Formulated by Georg Simon Ohm in 1827, it is
mathematically expressed as:
V = I × R
In this equation,
• V is the voltage in volts
• I is the current in amperes
• R is the resistance in ohms (Ω).
Ohm's Law states that for a given resistor at a constant temperature, the current flowing through it is directly
proportional to the voltage across it. Materials that follow this rule are called ohmic conductors.
Objective:
The objective of this experiment was to verify Ohm's Law by observing how current changes with varying
DC voltage across a fixed resistor. The experiment aimed to determine if the relationship between voltage
and current remains linear and if the measured values conform to Ohm's Law.
Procedures:
The experiment began by gathering the necessary equipment, including a variable DC power supply, two
digital multimeters (to be used as an ammeter and voltmeter), connecting wires, and a component board.
From the board, a resistor with a value of 6.65 Ω was selected. The circuit was assembled following a
provided diagram. One multimeter was connected in series with the resistor to measure the current, while the
other was connected in parallel across the resistor to measure the voltage drop. All connections were
carefully made to ensure a complete circuit.
After the circuit was confirmed to be correct, the DC power supply was turned on. The voltage was adjusted
in steps, starting from 10 V and decreasing down to 1 V. At each voltage level, the corresponding current
and voltage drop across the resistor were recorded.
Throughout the experiment, the resistor's value remained constant, so the current readings were expected to
change proportionally with the voltage, illustrating Ohm's Law. Adjustments were made to the ammeter's
range setting when inconsistencies were noticed due to changes in voltage.

CIRCUIT THEORY EE223 LAB № 1
Finally, all recorded values were organized into a data table to show the linear relationship between voltage,
current, and resistance.
Analysis of Experiment
The experimental data from Lab 01 provided a clear demonstration of Ohm's Law. The table of results
shows a linear relationship between the applied voltage and the resulting current for a fixed resistance of
6.65 Ω. A key observation is the proportionality: as the voltage increases (e.g., from 1 V to 10 V), the
current increases proportionally (from 0.15 mA to 1.49 mA). For example, at 5 V, the calculated current
(I=V/R=5/6.65) is approximately 0.75 mA, which matches the measured value. At 10 V, the calculated
current (I=10/6.65) is approximately 1.50 mA, which nearly matches the measured value of 1.49 mA.
The voltage drop across the resistor closely matches the supply voltage in each case, with only minor
deviations (e.g., -9.9 V instead of -10 V), indicating that the resistor behaves ideally by following Ohm's
Law with negligible energy loss elsewhere in the circuit. The minor discrepancies (≤ 1%) could be due to
instrument precision, parasitic resistances from wires and connections, or the power supply's internal
resistance.
The linear trend in the data confirms that the resistor is an ohmic material that obeys Ohm's Law across the
tested voltage range. When plotted, the data points form a straight line passing through the origin. The
gradient of the DC Voltage Supply (V) vs. Current (mA) graph represents the resistance of the circuit. A
steeper slope indicates higher resistance, while a shallower slope indicates lower resistance.
The calculated gradients at three different points on the graph were all approximately 6.67, confirming that
the resistance remained constant throughout the experiment. This consistent resistance across varying
voltage and current values suggests a linear relationship between voltage and current. This direct
proportionality is clearly demonstrated in the results table and the current-voltage graph provided. The 99-
100% agreement between theoretical and measured values suggests high experimental accuracy.
Conclusion
In conclusion, the experiment successfully verified Ohm's Law by demonstrating the linear relationship
between voltage and current for a fixed resistor. The objective of the lab was to observe how current
changes with varying DC voltage across a fixed resistor. A 6.65 Ω resistor was used, and the voltage was
adjusted from 10 V down to 1 V. At each voltage level, the corresponding current and voltage drop across
the resistor were recorded.
The results showed that as the voltage was reduced, the current also decreased proportionally, confirming
that for a given resistor at a constant temperature, the current is directly proportional to the voltage across it.
The resistance was measured to be approximately 6.65 Ω and remained constant even as the voltage supply
increased. This is further supported by the calculation of the gradients from the graph, which were all
similar. The consistent resistance across varying voltage and current values confirms that Ohm's Law is
obeyed over the range tested. The experimental data and graph clearly showed a linear trend, which
confirms that the resistor is an ohmic material and obeys Ohm's Law across the tested voltage range.

CIRCUIT THEORY EE223 LAB № 1
The strong agreement (99-100%) between the theoretical values and the measured values suggests a high
degree of experimental accuracy. Minor discrepancies, such as slight negative voltage drops or small
differences between calculated and measured values, are likely due to factors like instrument precision,
parasitic resistances from wires, or the internal resistance of the power supply.
Overall, the experiment reinforced the fundamental principle that for a constant resistance, voltage and
current change together in direct proportion, a concept essential for understanding and designing electrical
systems.
Reference:
• Prof. Todd Huffman Online Tutorials You-Tube
• A BEGINNER'S GUIDE TO CIRCUITS. Copyright © 2019 by Øyvind Nydal Dahl.
• CHATGPT AI
• BYJUS. (n.d.). From Ohm's Law Explanation:
https://byjus.com/physics/ohms-law/
• GCSE. (n.d.). From Current-Voltage Graphs:
https://studymind.co.uk/notes/current-voltage-
graphs/#:~:text=The%20slope%20of%20a%20current%2Dvoltage%20graph%20represents%20the%20resis
tance, slope%20indicates%20a%20lower%20resistance.
• Electronic Tutorials. (n.d.). Ohms Law and Power:
https://www.electronics-tutorials.ws/dccircuits/dcp_2.html