2026/2027 NECO Practical Physics Examination requires a solid understanding of practical experiments, laboratory procedures, specimen identification, measurements, calculations, and data analysis. This comprehensive 2026/2027 NECO Practical Physics Questions and Answers revision guide is designed to help candidates familiarize themselves with the format and types of questions commonly asked in the NECO Physics Practical exam.
Our practice questions, sample answers, and step-by-step explanations cover key areas of the NECO Physics syllabus, including electrical circuits, optics, mechanics, heat, measurements, graph plotting, and experimental observations. By working through these practical exercises, students can improve their accuracy, strengthen their problem-solving skills, and build confidence ahead of the examination.
Whether you’re looking for NECO Practical Physics past questions, Physics practical specimen guides, or NECO Physics practical revision materials, this resource provides everything you need to prepare effectively and maximize your chances of success in the 2026 NECO examination.
Examination Instructions
You are provided with:
- A retort stand with clamp
- A pendulum bob
- A light inextensible thread
- A metre rule
- A stopwatch
Carry out the experiment carefully and record all readings in the spaces provided.
Apparatus Required
- Retort stand
- Clamp
- Pendulum bob
- Thread
- Metre rule
- Stopwatch
Question 1
You are provided with the following specimens:
- Specimen A: Retort stand with clamp
- Specimen B: Pendulum bob
- Specimen C: Light inextensible thread
- Specimen D: Metre rule
- Specimen E: Stopwatch
Instructions
Use the specimens provided to carry out the experiment and answer the questions that follow.
(a) Assemble Specimens A, B, and C to form a simple pendulum.
Measure the length LLL of the pendulum for five different values between 30 cm and 70 cm.
For each length:
i. Set the pendulum into small oscillations.
ii. Measure the time ttt for 20 complete oscillations.
iii. Determine the period T=t20T = \frac{t}{20}T=20t.
iv. Calculate T2T^2T2.
Record your observations in a suitable table.
(b) Plot a graph of T2T^2T2 against LLL.
(c) Determine the gradient of the graph.
(d) Hence calculate the acceleration due to gravity, ggg.
(e) State two precautions taken during the experiment.
(f) State two possible sources of error.
Instructions to Candidates
- Assemble Specimens A, B and C to form a simple pendulum.
- Suspend the pendulum securely on the retort stand.
- Measure the length of the pendulum from the point of suspension to the centre of the bob.
- Release the pendulum gently from a small angle (less than 10°).
- Measure the time for 20 complete oscillations.
- Repeat the experiment for five different lengths.
- Record all observations in the table provided.
(a) Complete the Observation Table
| S/N | Length, L (m) | Time for 20 Oscillations, t (s) | Period, T = t/20 (s) | T² (s²) |
|---|---|---|---|---|
| 1 | 0.30 | 22.0 | 1.10 | 1.21 |
| 2 | 0.40 | 25.4 | 1.27 | 1.61 |
| 3 | 0.50 | 28.3 | 1.42 | 2.02 |
| 4 | 0.60 | 31.1 | 1.56 | 2.43 |
| 5 | 0.70 | 33.6 | 1.68 | 2.82 |
(b) Plot a Graph
Plot a graph of:
- Vertical Axis (Y-axis): T² (s²)
- Horizontal Axis (X-axis): Length L (m)
A straight-line graph should be obtained.
(c) Determine the Gradient of the Graph
Using two well-spaced points:
Point A = (0.30, 1.21)
Point B = (0.70, 2.82)
Gradient=2.82−1.210.70−0.30\text{Gradient}=\frac{2.82-1.21}{0.70-0.30}Gradient=0.70−0.302.82−1.21 =1.610.40=\frac{1.61}{0.40}=0.401.61 =4.03=4.03=4.03
Gradient = 4.03 s²/m
2026 NECO Practical Physics Questions and Answers
(d) Hence Determine the Value of g
Since
T2=4π2gLT^2=\frac{4\pi^2}{g}LT2=g4π2L
The slope of the graph is
4π2g\frac{4\pi^2}{g}g4π2
Therefore
g=4π2Slopeg=\frac{4\pi^2}{\text{Slope}}g=Slope4π2 4π2=39.484\pi^2=39.484π2=39.48
Hence
g=39.484.03g=\frac{39.48}{4.03}g=4.0339.48 g=9.80 m/s2g=9.80\,\text{m/s}^2g=9.80m/s2
Answer:
g≈9.8 m/s2g\approx9.8\,\text{m/s}^2g≈9.8m/s2
(e) State Four Precautions
Answer
- Ensure the pendulum swings through a small angle (less than 10°).
- Release the bob gently without applying extra force.
- Measure the length from the point of suspension to the centre of the bob.
- Record the time for many oscillations (e.g., 20) to reduce timing errors.
(f) State Four Sources of Error
Answer
- Human reaction time when starting and stopping the stopwatch.
- Air resistance acting on the pendulum bob.
- Friction at the point of suspension.
- Parallax error while reading the metre rule.
Expanded Worked Solution
Step 1: Measuring the Length
The length of the pendulum is not simply the length of the thread. It is measured from the point where the thread is attached to the support down to the centre of the pendulum bob. Measuring to the top or bottom of the bob would introduce systematic error.
Step 2: Timing the Oscillations
Instead of timing a single swing, the time for 20 complete oscillations is measured. This reduces the effect of human reaction time because any start/stop error is spread over many oscillations.
For example, if the time for 20 oscillations is 22.0 s:
T=22.020=1.10 sT=\frac{22.0}{20}=1.10\,\text{s}T=2022.0=1.10s
The period TTT is the time taken for one complete oscillation.
Step 3: Calculating T2T^2T2
The theoretical relationship for a simple pendulum involves the square of the period. Therefore, each measured period is squared.
For the first reading:
T=1.10 sT=1.10\,\text{s}T=1.10s T2=(1.10)2=1.21 s2T^2=(1.10)^2=1.21\,\text{s}^2T2=(1.10)2=1.21s2
This process is repeated for each length.
Step 4: Plotting the Graph
The graph of T2T^2T2 against LLL should produce a straight line because the theory predicts a direct proportional relationship:
T2∝LT^2 \propto LT2∝L
A straight line confirms that the experimental results are consistent with the theory of simple harmonic motion.
Step 5: Determining the Gradient
The gradient is calculated from two well-separated points on the best-fit line:
Gradient=ΔT2ΔL\text{Gradient}=\frac{\Delta T^2}{\Delta L}Gradient=ΔLΔT2
Substituting the values:
2.82−1.210.70−0.30=1.610.40=4.03\frac{2.82-1.21}{0.70-0.30} =\frac{1.61}{0.40} =4.030.70−0.302.82−1.21=0.401.61=4.03
Step 6: Calculating the Acceleration Due to Gravity
The relationship
T2=4π2gLT^2=\frac{4\pi^2}{g}LT2=g4π2L
shows that the gradient equals 4π2g\frac{4\pi^2}{g}g4π2. Rearranging gives:
g=4π2Gradientg=\frac{4\pi^2}{\text{Gradient}}g=Gradient4π2
Using the calculated gradient:
g=39.484.03=9.80 m/s2g=\frac{39.48}{4.03}=9.80\,\text{m/s}^2g=4.0339.48=9.80m/s2
This value is very close to the accepted acceleration due to gravity at the Earth’s surface, indicating that the experiment was carried out accurately.
2026 NECO Practical Physics Questions and Answers
Discussion of Results
The results show that:
- As the length of the pendulum increases, the period of oscillation also increases.
- The graph is approximately a straight line, confirming the theoretical relationship between T2T^2T2 and LLL.
- The calculated value of ggg agrees with the accepted value of approximately 9.81 m/s², demonstrating the reliability of the experiment within normal experimental error.
Educational Importance of the Experiment
This practical helps students:
- Understand simple harmonic motion.
- Learn how to measure time and length accurately.
- Develop graph-plotting and gradient calculation skills.
- Appreciate how experimental data can be used to determine physical constants such as the acceleration due to gravity.
Possible Viva Voce Questions and Answers
1. Why is the pendulum released gently?
To avoid giving it extra velocity, which could affect the motion and the measured period.
2. Why is the oscillation angle kept small?
Small angles ensure the motion closely approximates simple harmonic motion, making the formula valid.
3. Why are 20 oscillations timed instead of one?
Timing multiple oscillations reduces the percentage error due to human reaction time.
4. Why is the length measured to the centre of the bob?
The centre of mass of the bob is the correct reference point for the pendulum length.
5. What physical quantity is being determined in this experiment?
The acceleration due to gravity, ggg.
Examiner’s Marking Guide (20 Marks)
| Activity | Marks |
|---|---|
| Apparatus setup | 2 |
| Observation table | 4 |
| Calculations of TTT and T2T^2T2 | 4 |
| Graph plotting | 4 |
| Gradient determination | 2 |
| Calculation of ggg | 2 |
| Precautions and sources of error |
Question 3(a): Determination of Focal Length of a Convex Lens
Arrange the lens, object pin and screen.
Obtain a sharp image.
Measure:
- Object distance (u)
- Image distance (v)
Record:
u = 30 cm
v = 20 cm
3(b)
Calculate the focal length.
Answer
2026 NECO Practical Physics Questions and Answers
Question 4(a): Determination of Density
Measure:
Mass = 150 g
Initial water level = 40 cm³
Final water level = 60 cm³
4(b)
Calculate the density.
Answer
Volume displaced
= 60 − 40
= 20 cm³
Density
= 150 ÷ 20
= 7.5 g cm⁻³
Question 5(a): Simple Pendulum
Measure the time for 20 oscillations.
Length = 80 cm
Time = 36 s
5(b)
Determine:
(i) Period
(ii) Frequency
Answer
Period
= 36 ÷ 20
= 1.8 s
Frequency
f=1Tf = \frac{1}{T}f=
Examiner’s Expected Skills
Candidates should be able to:
Present calculations clearly with correct significant figures.
Take accurate measurements.
Record observations in well-organized tables.
Plot graphs using appropriate scales.
Calculate gradients correctly.
Apply standard physics formulas accurately.
State correct SI units.
Interpret experimental results.
Observe laboratory safety procedures.
Estimate percentage error where applicable.
