IB Physics IA Topics & Research Questions

Every IB Physics student eventually hits the same wall. You know the Internal Assessment is coming, and you have a rough area in mind — projectile motion, pendulums, friction, electricity, waves, thermal physics, circular motion — but a rough area is not a research question, and a research question is not the same thing as an investigation you can actually run in your school lab with the equipment you have.

This is where most of the difficulty in IB Physics IA topics and research questions actually lives. It's rarely a lack of ideas. It's the gap between an interesting idea and a focused, measurable, testable one. A good Physics IA topic has to survive contact with reality: your equipment, your timetable, your own understanding of the physics, and the six or seven weeks you realistically have to collect and analyse data.

I've worked with IB Physics students through this exact decision for several years, mostly the same conversation on repeat: "I like the idea, but I don't know how to turn it into something I can measure." This page is written to answer that conversation directly — what makes a topic workable, how to build a research question around it, and a substantial list of starting points organised by area of the syllabus.

What Makes a Good IB Physics IA Topic?

Examiners and supervisors are not looking for an unusual or dramatic idea. They're looking at whether the investigation was designed and carried out well. A strong topic simply makes that easier to achieve. In practice, the topics that work well tend to share the same handful of features.

• Clear physics connection. You can name the concept or relationship being tested in one sentence, without hedging.
• Genuinely measurable variables. The independent and dependent variables can be recorded with instruments your school actually has.
• Appropriate scope. Narrow enough to investigate properly in the time available, not a whole branch of physics.
• Available equipment. Motion sensors, data loggers, meter rulers, stopwatches, multimeters — not equipment you'd need to source specially.
• Repeatable measurements. You can take multiple trials at each value of the independent variable without the setup drifting.
• Manageable data collection. Enough data points to support a trend line and an uncertainty discussion, without an unrealistic number of trials.
• Room for meaningful analysis. The data should lend itself to a graph, a gradient, a comparison with theory — not just a table of numbers.
• Scope for evaluation. There should be real, identifiable sources of uncertainty and limitation to discuss honestly.
• A difficulty level that matches your understanding. You should be able to explain the underlying physics without leaning on a source you don't fully follow.
• Genuine interest. You will spend weeks on this. A topic you're mildly curious about is far easier to sustain than one chosen purely because it "sounds impressive."

Quick checklist

• I can state the physics relationship being tested in one sentence.
• I know exactly which two variables I'm measuring, and how.
• My school has the equipment, or something close enough.
• I can realistically collect this data within my available lab time.
• I understand the underlying physics without outside help.

How to Write an IB Physics IA Research Question

Once you have a topic area, the next job is turning it into a proper Physics Internal Assessment research question. Most workable questions follow a similar shape:

"How does independent variable affect dependent variable under controlled conditions?"

In simple terms:

• Independent variable — the one thing you deliberately change between trials.
• Dependent variable — the one thing you measure as a result.
• Controlled variables — everything else you hold constant, so the result you see is actually caused by the independent variable and not something else changing at the same time.

The framework is simple, but the discipline is in the detail: naming a range, a unit, and the conditions you're holding fixed. Here's how the same idea tightens up across three drafts.

30+ IB Physics IA Topics & Research Questions

Below is a working list of IB Physics IA topic ideas, organised by syllabus area, each with an example research question and the core variables involved. Treat these as starting points, not finished questions — you'll still need to narrow the range, decide on your equipment, and make the question your own. None of these is a "safe" route to a particular grade; the mark depends entirely on how well the investigation is designed, executed, analysed and evaluated.

Mechanics

Scroll horizontally on smaller screens to see the full table.

Thermal Physics

Waves

Electricity & Circuits

Fields

Modern Physics (school-lab friendly)

Easy vs Advanced IB Physics IA Topics

"Easy" does not mean low quality. A simple, well-controlled pendulum investigation with careful uncertainty analysis will usually outperform an ambitious modern-physics idea that the student can't fully explain or execute. Choose based on your equipment, your grasp of the underlying physics, and the time you actually have — not on how impressive the topic sounds.

How to Turn an Everyday Idea into an IB Physics IA Topic

Some of the strongest IA topics start as ordinary observations, not textbook chapters. The skill is in walking the observation through to a testable question.

For example: "Why does a phone battery get warm?" leads to internal resistance and power dissipation, which leads to a measurable investigation into how charging current affects battery surface temperature.

A few more everyday observations that can be developed the same way:

• Why does a ball bounce differently on different surfaces? → coefficient of restitution and surface material.
• Why does a bicycle slow down when you stop pedalling? → rolling resistance and air resistance as a function of speed.
• Why does the sound change with the length of a tube you blow across? → standing waves and resonant frequency.
• Why does water cool at different rates depending on the container? → surface area, material and heat loss.
• Why do different materials feel warmer or colder to the touch? → thermal conductivity.
• Why does a stretched string produce different sounds when you press it in different places? → string length and fundamental frequency.

Common Mistakes When Choosing IB Physics IA Topics

Most weak IAs don't fail because of the topic itself — they fail because of decisions made in the first week. The most common ones I see:

• Choosing a topic that's far too broad to investigate in the time available.
• Copying a topic or question from the internet without fully understanding it.
• Picking something purely because it "sounds impressive" rather than because it's workable.
• Having no clearly defined independent variable.
• Choosing a quantity that can't be measured reliably with available instruments.
• Planning around equipment the school doesn't actually have.
• Collecting too little data to support a real trend or uncertainty analysis.
• Ignoring uncertainty until the write-up, instead of planning for it from the start.
• Writing a research question that's needlessly complicated or multi-part.
• Choosing an investigation that sits outside the student's own understanding of the physics.
• Leaving topic selection until the last minute, which compresses every stage that follows.

How to Improve a Weak Physics IA Research Question

Here's the same tightening process applied across a few different areas — broad topic, first-draft question, the problem with it, and an improved version.

How Nivara Academy Supports IB Physics IA Students

Nivara Academy provides personalised academic mentoring for IB, IGCSE and CBSE students, with a particular focus on concept-driven learning rather than generic tutoring. For Physics IA support, that looks like:

• Making sense of the IA requirements and what the assessment is actually looking for.
• Brainstorming suitable topic directions based on the student's genuine interests and available equipment.
• Narrowing broad ideas into focused, workable research questions.
• Planning independent, dependent and controlled variables before data collection begins.
• Guidance on experimental design and setup.
• Support interpreting collected data and understanding what it shows.
• Clarifying the underlying physics concepts the student needs to understand.
• Feedback on the structure and reasoning of the write-up.
• Helping students identify weaknesses in their own approach before submission.
• One-to-one mentoring paced around the individual student, not a fixed curriculum.

IB Physics IA Topic Selection Checklist

Before committing to a topic, run it through this list:

• Is the physics concept clear?
• Can I measure the variables involved?
• Do I have suitable equipment available?
• Can I repeat the experiment reliably?
• Can I collect enough useful data?
• Can I control the important variables?
• Can I discuss uncertainty meaningfully?
• Is the scope manageable in the time I have?
• Do I genuinely understand the underlying physics?
• Can I explain, in my own words, why this investigation matters?

Frequently Asked Questions