JABATAN KEJURUTERAAN ELEKTRIK

DEE10133 MEASUREMENT DEVICES

LECTURER NAME NORLIZA BINTI ABD. RAZAK

TYPE OF ASSESSMENT PRACTICAL WORK 1

CHAPTER 1: DC Meters
TOPIC
(Apply DC ammeter and voltmeter in measuring current and voltage)

DURATION 3 WEEKS

DATE OF ASSESSMENT

REGISTRATION MARKS
NAME
NO. CLO02P CLO03A

STUDENT’S
INFORMATION

CLO02P:
Perform meter calibrating and measuring techniques using the correct measuring
equipment.
REMARKS
CLO03A (if related):
Demonstrate good communication skills in oral presentation within a stipulated time
frame.
 DEE10133 MEASUREMENT DEVICES

PRACTICAL WORK 1: DC Meters

(Apply DC ammeter and voltmeter in measuring current and voltage)
Perform meter calibrating and measuring techniques using
CLO02P PLO5 DP1, DP3, DP5
the correct measuring equipment.
Demonstrate good communication skills in oral presentation DP1, DP3, DP5,
CLO03A PLO9
within a stipulated time frame. NA1, NA5

A. OBJECTIVES

1. Construct a Basic Electrical Circuit:

• To construct a simple DC circuit using basic electrical components like a power supply, resistor,
ammeter, and voltmeter.

2. Measure Electrical Parameters:

• Using a multi-range DC ammeter, accurately measure the current flowing through the circuit.
• To measure the voltage across a resistor using a multi-range DC voltmeter.

B. LEARNING OUTCOME

1. To construct a simple electrical circuit and make precise connections using a breadboard or directly
with wires.

2. To use measuring Instruments:

• multi-range DC ammeter, and voltmeter to measure electrical quantities and understand how to
set the appropriate ranges on these instruments.

3. Data Analysis and Interpretation:

• Students will develop the ability to record, analyze, and interpret the data obtained from the
experiment, including identifying and explaining any discrepancies between theoretical and
experimental results.

C. TOPIC SUMMARY/ THEORY

1. Introduction to Electrical Circuits:

An electrical circuit is a path in which electrons from a voltage or current source flow. The complete
path is typically made up of a power source, conductive wires, and one or more load components such
as resistors.

2. Series Circuit:
In a series circuit, the components are connected end-to-end so that the current flows through each
component sequentially. The same current flows through all components, but the voltage is divided
among them based on their resistance.

3. Ohm’s Law:
Ohm’s Law states that the current (I) passing through a conductor between two points is directly
proportional to the voltage (V) across the two points and inversely proportional to the resistance (R)
between them. It is mathematically represented as V=IR

This fundamental law is used to calculate the unknown parameter (voltage, current, or resistance) in
 an electrical circuit if the other two parameters are known.

4. Measuring Instruments:
Ammeter: An instrument used to measure the current in a circuit. It is always connected in series with
the load so that the entire current flows through it. A multi-range ammeter allows for measuring
currents of different magnitudes by selecting the appropriate range.

Voltmeter: An instrument used to measure the voltage (potential difference) across two points in a
circuit. It is connected in parallel with the component across which the voltage is to be measured. A
multi-range voltmeter allows for measuring voltages of different magnitudes by selecting the
appropriate range.

5. Practical Application:
The experiment involves constructing a circuit with a known resistor and measuring the current flowing
through it and the voltage across it. By using Ohm's Law, students can validate the accuracy of their
measurements and gain a deeper understanding of the relationship between voltage, current, and
resistance.

D. MATERIAL / TOOLS

1. Materials:
• DC Power Supply:
Provides the necessary voltage for the circuit.
• Resistors:
10Ω and 1000 Ω
• Connecting Wires:
used to connect various components in the circuit.
• Breadboard
2. Tools:
• Multi-Range DC Ammeter
A device used to measure the current flowing through the circuit. The multi-range function allows
for measuring different magnitudes of current.
• Multi-Range DC Voltmeter
A device used to measure the voltage across a component in the circuit. The multi-range function
allows for measuring different magnitudes of voltage.
• Crocodile Clips (Optional)
• Multimeter (if separate from ammeter and voltmeter)
A versatile tool that can measure voltage, current, and resistance if separate ammeter and
voltmeter are not available.

E. GENERAL INSTRUCTION / SAFETY PROCEDURE

Category Instruction
General Instructions
- Read the experiment procedure thoroughly before starting.
Preparation - Verify the functionality of all equipment (e.g., power supply, ammeter,
voltmeter, resistors).
Connection Setup - Double-check all connections to ensure they are correct and secure.
- Set the ammeter and voltmeter to appropriate ranges based on
Meter Settings
expected values.
Data Recording - Accurately observe and record all readings from the meters.
- Turn off the power supply and disconnect the circuit after completing
Post-Experiment
the experiment.
- Store all equipment properly and ensure the work area is tidy.
 Safety Procedures
- Wear appropriate safety gear, such as safety goggles and insulated
Personal Safety
gloves.
Voltage Limits - Use low voltage (e.g., 5V) to minimize the risk of electric shock.
- Avoid exposed wires touching each other to prevent short circuits and
Short Circuit Prevention
potential burns.
- Ensure correct polarity for all components (positive and negative
Polarity Awareness
terminals).
- Do not exceed the current rating of the ammeter.
Equipment Safety
- Handle all instruments and components with care to prevent damage.
- Work in a dry environment and avoid handling components with wet
Environmental Safety
hands.
- Know the location of emergency equipment (e.g., fire extinguishers)
Emergency Preparedness and how to use them.
- Report faulty equipment immediately to avoid accidents.

F. WORK INSTRUCTION / PROCEDURE

1. Prepare the Components and Tools

2. Set Up the Power Supply:
3. Connect the Ammeter as shown in Figure 1.0
4. Connect the Resistor as shown in Figure 1.0
5. Integrate the Voltmeter as shown in Figure 1.0
6. Verify Connections: Ensure the ammeter is in series with the resistor, and the voltmeter is in parallel across
the resistor.
7. Set Ranges on Meters: Set the ammeter to the appropriate range based on the expected current
(e.g., 0-1A) and set the voltmeter to the appropriate range based on the expected voltage (e.g., 0-10V).
8. Power On the Circuit: Observe the readings on both the ammeter and voltmeter.
9. Record Measurements:
• Note down the current reading from the ammeter (in amperes).
• Record the voltage reading from the voltmeter (in volts).
• Record in Table 1.0
10. Calculate and Verify Resistance:
• Calculate the resistance using Ohm’s Law: R=V/I
• Compare the calculated resistance with the known value of the resistor.
• Record the calculations in the Explanation of Recorded Results Table.
11. Turn Off the Power Supply.
12. Disconnect the Circuit.
• Carefully disconnect all wires and components.
• Store the components and instruments properly.
13. Clean Up.
• Ensure the work area is tidy and free of any loose wires or components.
• Dispose of or store materials and tools as appropriate.
14. Review and Analyse Results:
• Discuss any discrepancies between theoretical and experimental results.
• Analyse any sources of error and suggest improvements for future experiments.
 Figure 1.0: Series Circuit
G. RESULT

a) Recorded Results Table:

Table 1.0: Measurement Data Table

Resistor Supply Measured Expected Measured Calculated Measured
(R) Voltage Voltage Current Current Resistance Resistance
(Vsupply) (V) (A) (A) (Ω) (Ω)
10Ω 5V
220Ω 10V
560Ω 10V
1000Ω 5V

b) Explanation of Recorded Results:

Table 2.0: Explanations Result
Discrepency
Expected Measured 𝒀𝒏 − 𝑿𝒏
Parameter %𝒆 = | | 𝑿 𝟏𝟎𝟎% Possible Causes of Error
Value Value 𝒀𝒏

Voltage (V)
Current (A)
Resistance (Ω) 10Ω
(Calculated)

Discrepency
Expected Measured 𝒀𝒏 − 𝑿𝒏
Parameter %𝒆 = | | 𝑿 𝟏𝟎𝟎% Possible Causes of Error
Value Value 𝒀𝒏

Voltage (V)
Current (A)
Resistance (Ω) 220Ω
(Calculated)
 Discrepency
Expected Measured 𝒀𝒏 − 𝑿𝒏
Parameter %𝒆 = | | 𝑿 𝟏𝟎𝟎% Possible Causes of Error
Value Value 𝒀𝒏

Voltage (V)
Current (A)
Resistance (Ω) 560Ω
(Calculated)

Discrepency
Expected Measured 𝒀𝒏 − 𝑿𝒏
Parameter %𝒆 = | | 𝑿 𝟏𝟎𝟎% Possible Causes of Error
Value Value 𝒀𝒏

Voltage (V)
Current (A)
Resistance (Ω) 1000Ω
(Calculated)

H. DISCUSSION
1. How does the accuracy of a multi-range ammeter compare with a single-range ammeter in this setup?
(2 marks)
2. Why is it critical to connect the voltmeter in parallel and the ammeter in series? (2 marks)
3. How does Ohm's Law validate the relationship between voltage, current, and resistance in your
observations? (2 marks)
4. What would happen if the resistor value is doubled in the same circuit? (2 marks)
5. In what real-world applications would you use the measurements obtained from this experiment?
(2 marks)

I. CONCLUSION

1. Restate the Purpose

2. Summarize Main Findings
3. Evaluate Success: Assess whether the experiment met its objectives and if the results supported the theoretical principles.
4. Discuss Accuracy and Errors
5. Suggest Improvements: Offer recommendations for enhancing the experiment, such as using more precise instruments or
refining procedures.
6. Highlight Significance: State the importance of the findings and their implications for understanding the studied concepts or
principles.