Choosing the right topic is one of the most important steps in the IB Physics Internal Assessment. A strong Physics IA topic is focused, measurable, and supported by a clear physical model or experiment that you can realistically carry out.

This guide gives you eighty IB Physics IA topic ideas across Mechanics, Electricity and Magnetism, Waves, Thermodynamics, Modern Physics, Materials, Astrophysics, and more. All topics have been checked for experimental feasibility and mathematical depth suitable for both SL and HL.

You will also find mini IA examples, guidance on turning a topic into a research question, and the most common mistakes students make when choosing their Physics IA direction.

What Makes a Good Physics IA Topic

A strong Physics IA topic should:

1. Be measurable with accessible equipment
2. Have one clear independent variable
3. Involve real physical modelling or equations
4. Allow for repeated trials and controlled conditions
5. Stay narrow enough for a 6 to 12 page report

Avoid topics that rely on theoretical explanations without data, require advanced university equipment, or depend on dangerous or uncontrolled conditions.

80 IB Physics IA Topic Ideas

Below are categories of safe, focused, and achievable Physics IA topics suitable for both SL and HL.

Mechanics IA Topics

1. Investigating how launch angle affects the range of a projectile
2. Determining the relationship between mass and acceleration on an incline
3. Analysing how surface texture influences friction coefficient
4. Investigating the effect of drop height on bounce efficiency of different balls
5. Determining air resistance by analysing terminal velocity of falling objects
6. Investigating how added mass affects rotational inertia of a wheel
7. Exploring the stopping distance of a rolling object under different slopes
8. Determining the spring constant using dynamic oscillations
9. Investigating how length affects the natural frequency of a pendulum
10. Modelling the motion of a trolley with constant driving force

Waves and Oscillations IA Topics

1. Investigating how string tension affects the frequency of standing waves
2. Determining how tube length affects resonance frequency in air columns
3. Analysing how material affects the damping of oscillations
4. Investigating the relationship between water depth and wave speed
5. Studying diffraction pattern changes with slit width
6. Determining how temperature affects the speed of sound
7. Investigating factors that affect amplitude in forced oscillations
8. Exploring the relationship between frequency and beat patterns
9. Measuring the refractive index of a liquid using light bending
10. Investigating the effect of angle of incidence on reflection intensity

Electricity and Magnetism IA Topics

1. Investigating how wire thickness affects electrical resistance
2. Determining how temperature influences resistance in metallic wires
3. Exploring the relationship between magnetic field strength and distance from a solenoid
4. Investigating how coil turns affect induced EMF in a generator
5. Determining how separation distance affects capacitor charging time
6. Investigating how magnet speed affects induced voltage in a coil
7. Exploring Lenz’s law using falling magnets and copper tubes
8. Determining how battery internal resistance changes under load
9. Investigating how distance affects force between two charged objects
10. Modelling the discharge curve of rechargeable batteries

Circular Motion and Gravitation IA Topics

1. Investigating how string length affects centripetal force requirements
2. Determining the relationship between rotation speed and tension in a whirling mass
3. Analysing how radius affects centripetal acceleration using sensors
4. Investigating orbital velocity using a rotating platform setup
5. Studying how varying mass distribution influences rotational stability
6. Modelling gravitational field strength using small scale analog experiments
7. Investigating how angular momentum is conserved in rotating systems
8. Determining the effect of mass placement on spinning object wobble
9. Investigating how friction affects motion on curved tracks
10. Exploring the relationship between torque and angular acceleration

Thermal Physics IA Topics

1. Investigating how insulation material affects cooling rate of liquids
2. Determining how the surface area of a container affects heat loss
3. Investigating how salt concentration affects water’s boiling point
4. Measuring the specific heat capacity of different metals experimentally
5. Investigating how air flow affects cooling rate
6. Determining emissivity of different surfaces by analysing radiation loss
7. Investigating thermal conductivity in composite materials
8. Exploring how humidity affects evaporation rate
9. Investigating how mass affects heat absorption rate
10. Studying the relationship between temperature and electrical resistance in thermistors

Modern Physics IA Topics

1. Investigating how light intensity affects photovoltaic cell output
2. Determining how wavelength affects photoelectric effect threshold (LED alternative method)
3. Exploring radioactive decay using safe simulations or datasets
4. Investigating the relationship between LED color and forward voltage
5. Studying half life using decay curves of chemical reactions as analogs
6. Modelling electron diffraction patterns using data sources or school apparatus
7. Investigating how polarisation affects transmitted light intensity
8. Exploring the relationship between photon energy and LED efficiency
9. Analysing energy loss in inelastic collisions using motion sensors
10. Investigating how the stopping potential changes with light frequency (setup dependent)

Astrophysics and Space IA Topics

1. Investigating how orbital radius affects orbital period using Kepler’s data
2. Modelling the luminosity of stars using the Stefan Boltzmann law
3. Determining the relationship between star temperature and peak wavelength
4. Investigating exoplanet detection using transit simulation data
5. Analysing how altitude affects atmospheric pressure using real datasets
6. Modelling gravitational field variation with altitude
7. Studying distance modulus relationships using known star clusters
8. Investigating the relationship between solar angle and irradiance
9. Analysing spectral absorption patterns in starlight data
10. Investigating day length variation using astronomical models

Materials and Engineering IA Topics

1. Investigating how diameter affects breaking strength of wires
2. Determining the Young’s modulus of different materials
3. Investigating how cross sectional shape affects beam bending
4. Exploring stress strain relationships in elastic materials
5. Determining how temperature affects elasticity of rubber bands
6. Investigating frictional force differences in various materials
7. Exploring how surface roughness affects rolling resistance
8. Determining how adhesives fail under different loads
9. Investigating how curvature affects structural stability
10. Exploring how water absorption affects mechanical strength of materials

Mini IA Examples With Clear Physics Focus

1. Investigating how string tension affects standing wave frequency

Possible research question
How does tension influence the fundamental frequency of a vibrating string

Math and physics involved
Wave equations, tension formula, linear relationships, uncertainty analysis

Data
Frequency measurements at different applied tensions

What to explore
Compare the linear model with experimental results and analyse sources of error.

2. Investigating cooling rate of liquids with different insulation materials

Possible research question
How does insulation material influence the cooling rate of hot water

Math and physics involved
Exponential cooling curves, curve fitting, thermal conductivity concepts

Data
Temperature readings over time for each insulation type

What to explore
Compare decay constants and evaluate effectiveness based on data.

3. Investigating magnetic induction with changing coil turns

Possible research question
How does changing the number of turns in a coil affect the induced EMF during magnetic flux change

Math and physics involved
Faraday’s law, linear models, rate of change calculations

Data
Voltage readings across different coil configurations

What to explore
Model induced EMF against turns and analyse proportionality.

Common IA Topic Mistakes To Avoid

1. Choosing a topic requiring unsafe or advanced equipment
2. Selecting a variable that cannot be measured reliably
3. Using too many independent variables
4. Writing theoretical explanations instead of analysing data
5. Choosing a project that cannot be repeated for reliability
6. Ignoring calibration and uncertainty
7. Selecting a topic that depends heavily on simulations without justification

How To Turn a Physics Topic Into a Research Question

A topic becomes effective when it becomes measurable and specific.

Examples:

Topic
Projectile motion

Research question
How does launch angle affect the horizontal range of a projectile launched at constant force

Topic
Resistance in wires

Research question
How does wire thickness influence electrical resistance under constant temperature

This format keeps your IA focused and mathematical.

Final Tips for Choosing Your Physics IA Topic

• Choose a variable you can measure accurately
• Keep the setup simple and repeatable
• Use clear physics models and compare them with data
• Start testing early to find workable ranges
• Keep the scope narrow and focused

A good Physics IA blends curiosity, clear data, and strong analysis. The ideas above can help you choose a topic that is practical, meaningful, and achievable.

If you need personalised guidance for choosing your IA topic or improving your investigation, you can sign up on Baccalytics and get one on one support from experienced IB tutors.