IB Physics IA Examples and Topics for 2026: Your Complete Guide to Success

The IB Physics Internal Assessment (IA) represents one of the most significant components of your IB Diploma Programme journey, accounting for 20% of your final grade in both Standard Level (SL) and Higher Level (HL). With the updated curriculum that began in August 2023 and the first assessments taking place in May 2025, students preparing for their 2026 examinations need to understand the latest requirements, assessment criteria, and most importantly, how to choose compelling topics that can secure top marks.

Understanding the IB Physics IA for 2026

What Is the IB Physics IA?

The IB Physics Internal Assessment is now officially called the “Scientific Investigation.” This is a student-designed experimental investigation where you formulate your own research question, design and conduct an experiment, collect and analyze data, and present your findings in a structured scientific report. The maximum word count is 3,000 words, giving you ample space to demonstrate your understanding of physics concepts and scientific methodology.

Key Changes in the 2025-2026 Assessment Cycle

The IB has introduced several important updates that affect students completing their IA in 2026:

Collaborative Work Allowed: Students can now work in small groups during the data collection phase. However, each student must focus on distinct independent or dependent variables and submit an individual report with unique analysis.

Streamlined Assessment Criteria: The IA is now assessed using four equally weighted criteria, each worth 6 marks, totaling 24 marks. This applies identically to both SL and HL students.

Word Count Increase: The maximum word count has increased from 2,500 to 3,000 words, allowing for more comprehensive analysis and evaluation.

The Four Assessment Criteria Explained

Understanding what examiners are looking for is crucial to achieving a high score. Here’s a breakdown of each criterion:

Criterion A: Design (6 marks)

This criterion evaluates how well you plan your scientific investigation. Examiners look for:

• A clearly defined, focused research question with measurable variables
• A detailed methodology that allows for reproducibility
• Well-identified independent, dependent, and controlled variables
• Justified experimental design decisions
• Consideration of safety, ethical, or environmental concerns where relevant

Pro Tip: Your research question should follow the format: “How does [independent variable] affect [dependent variable]?” This structure ensures clarity and focus.

Criterion B: Data Collection and Processing (6 marks)

This criterion focuses on the quality of your experimental work and data analysis:

• Sufficient data points with repeated trials to establish reliable trends
• Clear, well-organized tables and graphs with proper units and labels
• Appropriate use of significant figures throughout
• Correct processing of data with relevant calculations
• Proper treatment of uncertainties and error propagation

Remember: Raw data alone isn’t enough. You must process and transform your data meaningfully to demonstrate understanding.

Criterion C: Conclusion (6 marks)

Your conclusion must directly answer your research question using evidence from your data:

• Clear statement addressing the research question
• Connection to relevant physics theory and principles
• Discussion of relationships or patterns identified in the data
• Acknowledgment of limitations and their impact on reliability
• Appropriate use of uncertainties in drawing conclusions

Criterion D: Evaluation (6 marks)

This criterion assesses your critical thinking and scientific maturity:

• Identification of specific strengths and weaknesses in your experimental design
• Discussion of systematic and random errors with quantitative impact
• Realistic, actionable improvements that address identified limitations
• Honest reflection on the investigation’s overall success

Important: Avoid generic statements like “human error” or “use better equipment.” Be specific about what went wrong and how it could be improved.

Top IB Physics IA Topics for 2026

Choosing the right topic is perhaps the most critical decision you’ll make. Here are proven topic ideas across different areas of physics, each capable of producing excellent results.

Mechanics Topics

1. Projectile Motion and Launch Angle Research Question: How does the launch angle (15°, 30°, 45°, 60°, 75°) affect the horizontal range of a projectile?

This classic investigation allows you to explore fundamental mechanics while collecting precise, repeatable data. Use motion sensors or video analysis software to track projectile paths accurately.

2. Coefficient of Friction Investigation Research Question: How does the surface material (wood, glass, sandpaper, metal, plastic) affect the coefficient of static friction with a rubber block?

This hands-on investigation is highly practical and produces clear, measurable results. Vary the normal force and create multiple trials for robust data.

3. Pendulum Period and Length Research Question: How does the length of a simple pendulum (20cm, 40cm, 60cm, 80cm, 100cm) affect its period of oscillation?

While this is a common topic, you can add creativity by investigating how different fluids (air, water, oil) affect damping, or by exploring the impact of amplitude on period.

4. Terminal Velocity of Coffee Filters Research Question: How does the number of stacked coffee filters affect their terminal velocity when dropped?

This investigation beautifully demonstrates air resistance and terminal velocity. Coffee filters reach terminal velocity quickly, making data collection manageable.

Electricity and Magnetism Topics

5. Resistance and Temperature Research Question: How does temperature (20°C, 30°C, 40°C, 50°C, 60°C) affect the electrical resistance of a copper wire?

This investigation explores the relationship between temperature and resistance in conductors. Use a water bath to control temperature precisely and a multimeter for accurate resistance measurements.

6. Electromagnetic Induction Research Question: How does the number of coil turns (50, 100, 150, 200, 250) affect the induced EMF when a magnet passes through a solenoid?

This topic allows you to verify Faraday’s Law experimentally while collecting quantitative data on electromagnetic induction.

7. Solar Panel Efficiency Research Question: How does the angle of incidence (0°, 15°, 30°, 45°, 60°, 75°, 90°) affect the power output of a photovoltaic cell?

With growing interest in renewable energy, this investigation has real-world relevance and produces clear trends that can be analyzed mathematically.

8. Internal Resistance of a Battery Research Question: How does the load resistance affect the terminal voltage of a battery, and what is its internal resistance?

This investigation combines practical circuit work with theoretical understanding of battery behavior.

Waves and Optics Topics

9. Resonance in Strings Research Question: How does the tension in a string affect the resonant frequency of the second harmonic standing wave?

Use a vibration generator to produce standing waves and vary the tension systematically. This investigation connects wave theory with practical observations.

10. Refractive Index and Concentration Research Question: How does the concentration of sugar solution (0%, 10%, 20%, 30%, 40%) affect its refractive index?

This investigation can be done with simple equipment like a laser pointer and is highly relevant to understanding Snell’s Law.

11. Sound Attenuation Research Question: How does the frequency of a sound wave (200Hz, 400Hz, 600Hz, 800Hz, 1000Hz) affect its attenuation coefficient through different materials?

Use a sound level meter and various materials to explore how sound intensity decreases with distance and frequency.

12. Single-Slit Diffraction Research Question: How does the slit width affect the width of the central maximum in a single-slit diffraction pattern?

This investigation explores wave behavior of light and can produce beautiful, measurable diffraction patterns with a simple laser setup.

Thermodynamics Topics

13. Specific Heat Capacity Determination Research Question: How does the mass of water (100g, 200g, 300g, 400g, 500g) affect the temperature increase when supplied with a constant amount of electrical energy?

This practical investigation allows you to determine specific heat capacity experimentally while exploring energy transfer.

14. Newton’s Law of Cooling Research Question: How does the insulation material (foam, cotton, aluminum foil, plastic, fiberglass) affect the cooling rate of hot water?

This investigation explores exponential decay in thermal systems and has practical applications in everyday life.

15. Efficiency of Heat Engines Research Question: How does the temperature difference between hot and cold reservoirs affect the efficiency of a simple heat engine model?

Build a simple heat engine and measure work output versus heat input to explore thermodynamic efficiency.

Modern Physics Topics

16. LED Wavelength and Voltage Research Question: How does the forward voltage relate to the wavelength of light emitted by different colored LEDs?

This investigation explores quantum physics principles and the photoelectric effect using accessible materials.

17. Half-Life Simulation Research Question: How does the number of dice/coins affect the accuracy of simulating radioactive decay and determining half-life?

While this uses simulation rather than actual radioactive materials, it demonstrates exponential decay and statistical behavior effectively.

Interdisciplinary Topics

18. Biomechanics of Jumping Research Question: How does the angle of knee bend affect the vertical height achieved in a standing jump?

This combines physics with biology and can use video analysis for accurate measurements.

19. Acoustic Properties of Musical Instruments Research Question: How does the length of an air column in a bottle affect the resonant frequency when blown across?

This investigation explores standing waves in air columns and has clear musical applications.

20. Viscosity and Temperature Research Question: How does temperature affect the viscosity of different cooking oils measured by terminal velocity of falling spheres?

This investigation combines fluid dynamics with practical applications in cooking and engineering.

Tips for Choosing Your Perfect IA Topic

Consider Your Resources

Select a topic that can be completed with equipment available in your school laboratory or easily obtained materials. Don’t choose topics requiring specialized university-level equipment.

Personal Interest Matters

Choose something you’re genuinely curious about. Your enthusiasm will show in your analysis and writing, potentially earning personal engagement points.

Ensure Measurability

Your independent variable must be quantifiable and easy to control. Your dependent variable must produce clear, measurable results with reasonable precision.

Check Feasibility with a Pilot Test

Before committing to your topic, conduct a quick pilot experiment to ensure you can collect meaningful data. This prevents wasting time on an unworkable investigation.

Avoid These Common Pitfalls

• Topics too complex for the available time and resources
• Research questions with too many variables
• Investigations that produce insufficient data points
• Topics requiring dangerous materials or procedures
• Overly ambitious projects that can’t be completed within deadlines

How to Structure Your IB Physics IA

Title Page

Include your research question, candidate number, and word count.

Introduction (200-300 words)

Present your research question, explain its relevance, and provide theoretical background on the physics concepts involved.

Methodology (400-500 words)

Describe your experimental setup in detail, including:

• Diagram of apparatus
• List of materials
• Variables (independent, dependent, controlled)
• Step-by-step procedure
• Safety considerations

Data Collection and Processing (500-700 words)

Present raw data in clear tables, then process this data with appropriate calculations. Include graphs with trendlines, error bars, and proper labels.

Analysis and Conclusion (400-500 words)

Answer your research question using evidence from your data. Connect findings to physics theory and discuss the significance of your results.

Evaluation (300-400 words)

Critically evaluate your investigation’s strengths and weaknesses. Identify specific sources of error and suggest realistic improvements.

Bibliography

Cite all sources using a consistent format (APA or MLA).

Timeline for Your 2026 IA

Most schools require IA submissions between January and March 2026, though this varies. Here’s a suggested timeline:

3-4 months before deadline: Choose topic and conduct pilot tests 2-3 months before deadline: Conduct full experiment and collect data 1-2 months before deadline: Write first draft 2-4 weeks before deadline: Revise based on teacher feedback 1 week before deadline: Final polish and submission

Common Mistakes to Avoid

Insufficient Data

Collect at least 5 data points for each variable level, with multiple trials for reliability. Single trials produce unreliable results.

Ignoring Uncertainties

Every measurement has uncertainty. Calculate and propagate these through your analysis to strengthen your evaluation.

Generic Evaluation

Avoid phrases like “I could have been more careful” or “The equipment wasn’t good enough.” Be specific about limitations and their quantitative impact.

Poor Research Question Format

Vague questions like “How does temperature affect resistance?” need specificity. Better: “How does temperature (20°C to 60°C in 10°C intervals) affect the resistance of a 1-meter copper wire?”

Plagiarism

Always cite sources properly. Using existing IA ideas is acceptable and won’t lose you marks, but your write-up must be entirely your own work.

Resources for Success

IB Physics Data Booklet

Your data booklet contains formulas and constants that can inspire investigations. Use it as a starting point for topic ideas.

Online Tools

• Video analysis software (Tracker, Logger Pro)
• Data collection apps (Phyphox)
• Graphing tools (Desmos, Excel)
• Simulation software (PhET Interactive Simulations)

Teacher Support

Your physics teacher is your most valuable resource. Schedule regular check-ins to discuss progress and get feedback on your methodology.

Final Thoughts

The IB Physics IA is an opportunity to showcase your scientific thinking, experimental skills, and understanding of physics concepts. With careful topic selection, thorough planning, and attention to the assessment criteria, you can create an investigation that not only earns top marks but also deepens your appreciation for experimental physics.

Remember that originality isn’t required—around 25,000 students complete physics IAs annually, so most topics have been explored before. What matters is the quality of your experimental design, the depth of your analysis, and the thoughtfulness of your evaluation.

Start early, choose a topic you’re passionate about, collect robust data, and write with clarity and precision. Your Physics IA journey begins with that first research question—make it count, and let your scientific curiosity guide you toward success in 2026 and beyond.