Required practicals · Physics
Physics required practicals
AQA sets 10 required practicals for Physics. This page covers the AQA specification only — not Edexcel, OCR or any other exam board — so check with your teacher which board you’re actually sitting before relying on it. (MarkMatch as a whole is AQA-only for now, too.)
Every practical below has a real method to know, but not everything is equally exam-critical — the greenbox under each one is what actually costs marks if you don’t know it; the grey box is useful context you don’t need to stress about memorising.
RP1
Specific heat capacity
Determine the specific heat capacity of a material by measuring the energy transferred to change its temperature.
Equipment
Block (or liquid) of known mass, Immersion heater, Joulemeter (or ammeter, voltmeter and stopwatch), Thermometer, insulation (e.g. cotton wool)
Method
- Measure the mass of the block/liquid.
- Insert the heater and a thermometer into the block/liquid, wrapping it in insulation to reduce energy loss.
- Record the starting temperature.
- Switch on the heater for a measured time, recording energy supplied (from the joulemeter, or calculated as **E = IVt** from ammeter/voltmeter readings and time).
- Record the highest temperature reached; calculate the temperature change.
- Calculate specific heat capacity using **c = E ÷ (m × ΔT)**.
You definitely need to know
- Energy transferred, E = m × c × ΔT — rearrange for c using the practical’s measured values.
- If using ammeter/voltmeter instead of a joulemeter: E = I × V × t (current × potential difference × time).
- Insulation reduces (does not eliminate) energy loss to the surroundings — a source of experimental error worth naming.
- Specific heat capacity is the energy needed to raise 1 kg of a substance by 1°C.
Common exam question types
- Calculate specific heat capacity from given mass, energy and temperature change.
- Calculate energy supplied using E = IVt given current, voltage and time.
- Explain why the block/liquid is insulated.
- Explain a source of error and its effect on the calculated value of c (usually: heat lost to surroundings makes the calculated c too low, since less of the true energy went into the object).
RP2Physics only
Thermal insulation
Investigate the effect of insulation (thickness/material) on the rate of cooling of water.
Equipment
Beakers of hot water, Insulating material (e.g. bubble wrap, of different thicknesses), Thermometer, lid, stopwatch
Method
- Wrap identical beakers of hot water in different thicknesses/types of insulation (leaving one uninsulated as a comparison).
- Record the starting temperature of the water in each.
- Record temperature at regular time intervals (e.g. every minute) for a set total time.
- Plot temperature against time for each; compare how quickly each cools.
| Independent | Thickness (or type) of insulation |
| Dependent | Temperature of the water over time (or overall temperature drop) |
| Control | Starting temperature and volume of water; Beaker size/material; Room temperature |
You definitely need to know
- More/thicker insulation reduces the rate of energy transfer to the surroundings, so the water cools more slowly.
- A lid is used to reduce energy loss by evaporation from the water surface — a common control/improvement answer.
- This links to the general rule: energy is always transferred from a hotter object to its cooler surroundings until they reach the same temperature.
Good to know — less essential
- This is Physics-only (not Combined Science Trilogy).
Common exam question types
- Describe the pattern shown by a set of cooling graphs (which insulation is most effective, and how you know).
- Explain why a lid is used on the beaker.
- Explain, in terms of energy transfer, why thicker insulation gives a slower rate of cooling.
RP3
Resistance factors
Investigate how the length (and other factors) of a wire affects its resistance.
Equipment
Test wire on a metre ruler, Ammeter, voltmeter (or multimeter), Power supply, crocodile clips, connecting leads
Method
- Set up a circuit with the wire, ammeter (in series) and voltmeter (in parallel across the wire).
- Connect crocodile clips to a measured length of wire (e.g. 10 cm).
- Record current and potential difference; calculate resistance using **R = V ÷ I**.
- Repeat at different wire lengths, keeping the same wire (same material/thickness) each time.
- Plot resistance against length.
| Independent | Length of wire |
| Dependent | Resistance (calculated from V and I) |
| Control | Wire material and cross-sectional area (thickness); Temperature (keep current low/brief readings to avoid the wire heating up) |
You definitely need to know
- Resistance = Potential difference ÷ Current (R = V ÷ I).
- Longer wire = MORE resistance — a directly proportional relationship (a straight line through the origin on a resistance-length graph).
- Keep readings brief / current low so the wire doesn’t heat up — heating changes resistance and would contaminate the results (a very common control-variable answer).
- Ammeter always connected in SERIES; voltmeter always connected in PARALLEL across the component being measured.
Common exam question types
- Calculate resistance from given current and voltage.
- Describe the relationship shown by a resistance-length graph.
- Explain why the wire shouldn’t be left connected for long periods.
- Explain how the circuit is set up (series/parallel placement of meters).
RP4
I–V characteristics
Investigate the I-V (current-potential difference) characteristics of a resistor, a filament lamp, and a diode.
Equipment
Component under test (resistor / filament lamp / diode), Ammeter, voltmeter, Variable resistor, power supply, Connecting leads
Method
- Set up the circuit with the test component, ammeter in series, voltmeter in parallel across it, and a variable resistor to change current.
- Adjust the variable resistor to take a range of current/voltage readings, including both directions (reverse the supply for negative values).
- Record current and potential difference at each setting.
- Plot current (y-axis) against potential difference (x-axis) for each component.
| Independent | Potential difference across the component (set via the variable resistor) |
| Dependent | Current through the component |
| Control | Which single component is under test at a time; Temperature (kept low/brief readings for the resistor and diode, since the filament lamp is the one meant to heat up) |
You definitely need to know
- Resistor at constant temperature: straight line through the origin (current directly proportional to voltage — obeys Ohm’s law).
- Filament lamp: curve that flattens (resistance increases) as current increases, because the filament heats up and resistance rises with temperature.
- Diode: current flows in only ONE direction — near-zero current in reverse, and a "threshold" voltage before current flows in forward bias.
- A steeper gradient on an I-V graph means LOWER resistance; the gradient decreasing means resistance is increasing.
Common exam question types
- Sketch or identify the I-V graph for a named component.
- Explain the shape of the filament lamp’s graph in terms of temperature and resistance.
- Explain the diode’s behaviour in forward and reverse bias.
- Calculate resistance at a given point on a graph using R = V/I.
RP5
Density
Measure the density of regular and irregular solid objects, and of a liquid.
Equipment
Balance, Ruler/vernier calipers (regular solids), Eureka can + measuring cylinder (irregular solids), Measuring cylinder (liquids)
Method
- Regular solid: measure mass with a balance; measure dimensions with a ruler/calipers and calculate volume (e.g. length × width × height for a cuboid).
- Irregular solid: measure mass, then find volume by displacement — lower the object into a Eureka can (or measuring cylinder) full of water and measure the volume of water displaced.
- Liquid: measure the mass of an empty measuring cylinder, then with a known volume of liquid in it; subtract to find the liquid’s mass.
- Calculate density using **ρ = m ÷ V** for each.
You definitely need to know
- Density = mass ÷ volume (ρ = m/V), units kg/m³ or g/cm³.
- Displacement method: volume of the solid = volume of water displaced (final reading − initial reading on the measuring cylinder).
- For a liquid, always subtract the mass of the empty container first — a very common lost mark if skipped.
- A ruler's reading error (typically ±0.5mm or ±1mm) is a FIXED absolute error — measuring a SMALL object with it gives a much larger PERCENTAGE error than measuring a large one with the same ruler, since the same fixed error is a bigger fraction of a smaller true value.
Common exam question types
- Calculate density from given mass and volume.
- Describe the method for finding the volume of an irregular solid.
- Explain why the measuring cylinder’s empty mass must be subtracted when finding a liquid’s density.
- Explain why measuring the diameter of a small object with a ruler gives a large percentage error, and suggest how to reduce it (eg a micrometer/vernier calipers, or measuring several objects stacked together and dividing).
RP6
Force and extension
Investigate the relationship between force and extension for a spring (Hooke’s law).
Equipment
Spring, clamp stand, Slotted masses, Ruler (fixed in place), Set square (to read the ruler accurately)
Method
- Clamp the spring vertically; measure and record its natural (unstretched) length.
- Add a mass, let the spring settle, and measure the new length; calculate extension = new length − natural length.
- Repeat, adding masses one at a time, recording extension at each force (weight = mass × g).
- Plot force (x-axis) against extension (y-axis) — the gradient is the spring constant.
- Continue past the point where the line stops being straight, to find the limit of proportionality.
| Independent | Force applied (mass added, converted to weight) |
| Dependent | Extension of the spring |
| Control | Same spring throughout; Measuring from the same fixed point each time |
You definitely need to know
- Force = spring constant × extension (F = ke) — this only holds up to the limit of proportionality.
- A set square (not just eyeballing) is used against the ruler to take an accurate reading at eye level — reduces parallax error.
- The gradient of a force-extension graph = the spring constant, k.
- Beyond the limit of proportionality, the graph curves — the spring no longer extends proportionally to force, and won’t return to its original length once force is removed (inelastic deformation).
Common exam question types
- Calculate spring constant from the gradient of a force-extension graph, or from a single F and e value.
- Identify the limit of proportionality on a graph and explain what happens beyond it.
- Explain how to reduce parallax error when reading extension.
- Calculate the energy stored in a stretched spring (½ke², Higher tier, within the limit of proportionality).
RP7
Force and acceleration
Investigate the effect of varying force (or mass) on the acceleration of an object.
Equipment
Trolley (or dynamics cart) on a track, String, pulley, slotted masses (to provide force), Light gates + data logger (or ticker timer)
Method
- Set up a trolley on a track connected over a pulley to a hanging mass, which provides the accelerating force.
- Use light gates (or a ticker timer) to measure velocity at two points, and the time between them, to calculate acceleration.
- Vary the force (move masses from the trolley to the hanger, keeping total mass of the system constant) and record acceleration each time.
- Repeat, this time keeping force constant and varying the total mass being accelerated (add masses onto the trolley itself).
- Plot acceleration against force, and separately acceleration against 1/mass.
| Independent | Force (in part 1) or total mass (in part 2) |
| Dependent | Acceleration |
| Control | Total mass of the system while varying force (masses moved between trolley and hanger, not added/removed); Track friction/slope (often compensated for by tilting the track slightly) |
You definitely need to know
- Force = mass × acceleration (F = ma) — the core relationship this practical demonstrates.
- Acceleration is DIRECTLY proportional to force (at constant mass), and inversely proportional to mass (at constant force).
- Moving masses between the trolley and the hanger (rather than adding extra masses) keeps the TOTAL mass of the system constant while varying force — a key control easy to get backwards.
- The track is sometimes tilted slightly to compensate for friction, so the only unbalanced force is genuinely the pulling force.
Common exam question types
- Calculate acceleration from velocity and time data (or from force and mass).
- Describe the relationship between force and acceleration shown by the graph.
- Explain why masses are moved between the trolley and hanger rather than added separately.
- Explain why the track might be tilted slightly before starting.
RP8
Waves in a ripple tank
Investigate the suitability of measuring the frequency, wavelength and speed of waves in a ripple tank (water) and on a string.
Equipment
Ripple tank, wave generator, lamp/strobe, Vibration generator, string/rope, pulley, masses
Method
- Ripple tank: set the wave generator to produce ripples of a known frequency; use a lamp (or strobe) to project the ripple pattern and measure wavelength between successive wave crests (shadows) on paper below.
- Calculate wave speed using **v = f × λ**.
- String: attach one end of a string/rope to a vibration generator, run it over a pulley with masses to create tension, and adjust frequency until a clear standing wave pattern forms.
- Measure the wavelength from the standing wave pattern (distance between nodes) and use the set frequency to calculate speed.
You definitely need to know
- Wave speed = frequency × wavelength (v = f × λ) — the core equation this practical measures.
- Frequency is set on the signal/wave generator; wavelength is measured directly from the ripple/standing-wave pattern.
- A strobe light (matched to the wave frequency) can make the ripple pattern appear to "freeze," making wavelength easier to measure accurately.
Common exam question types
- Calculate wave speed from measured frequency and wavelength.
- Describe how wavelength is measured in the ripple tank / on the string.
- Explain a source of measurement error (e.g. parallax when measuring wavelength) and how to reduce it.
RP9Physics only
Light and refraction
Investigate the refraction of light through different substances, and how this relates to refractive index.
Equipment
Glass or Perspex block, Ray box/laser, Protractor, paper, pencil
Method
- Place the block on paper and trace around its outline.
- Direct a ray of light at the block at a chosen angle of incidence, marking the incident ray, and where the ray exits the other side.
- Remove the block and use a ruler to draw in the refracted ray inside the block (connecting entry and exit points), and the emergent ray.
- Draw a normal line (perpendicular to the block’s surface) at the point of entry; measure the angle of incidence and angle of refraction with a protractor.
- Repeat at several different angles of incidence.
| Independent | Angle of incidence (or the block material, if comparing different substances) |
| Dependent | Angle of refraction (used to calculate refractive index) |
| Control | Same block/material throughout a set of angle repeats; Same ray box/light source and its brightness |
You definitely need to know
- Light bends TOWARDS the normal when entering a denser medium (e.g. air → glass), and AWAY from the normal when leaving it (glass → air).
- The angle of incidence and angle of refraction are always measured from the NORMAL, not the surface itself.
- Refractive index, n = sin(angle of incidence) ÷ sin(angle of refraction) (Higher tier).
- The ray exiting the far side of the block (the emergent ray) is parallel to the original incident ray, just laterally displaced (shifted sideways).
Good to know — less essential
- This is Physics-only (not Combined Science Trilogy).
Common exam question types
- Draw/measure the path of a ray of light through a rectangular block, including the normal.
- Calculate refractive index given angles of incidence and refraction.
- Explain, in terms of speed, why light bends when it enters a different medium.
- Explain why the emergent ray is parallel to the incident ray.
RP10
Infrared radiation
Investigate how the nature (colour/texture) of a surface affects the emission and absorption of infrared radiation.
Equipment
Leslie cube (four different surface finishes, e.g. matte black, white, shiny silver, dull silver), Infrared detector (or thermometers), Kettle/hot water, stopwatch
Method
- Fill the Leslie cube with hot water (or heat it evenly) so all four faces start at the same temperature.
- Hold an infrared detector at the same fixed distance from each face in turn, and record the reading.
- Compare readings across the four surfaces to rank them by how much infrared radiation they emit.
- A similar set-up (surfaces at a set distance from a heat source) can instead test ABSORPTION, by measuring temperature rise of a thermometer/sensor behind each surface.
| Independent | Nature (colour/texture) of the surface tested |
| Dependent | Infrared detector reading (or temperature change of a sensor behind the surface, for the absorption version) |
| Control | Starting temperature (all faces the same); Distance of the detector/sensor from the surface; Volume of hot water in the cube (or distance from the heat source, for absorption) |
You definitely need to know
- Matte/dull BLACK surfaces are the best emitters AND absorbers of infrared radiation.
- Shiny/silver surfaces are the poorest emitters and absorbers (they reflect radiation instead) — this is why they’re used in things like emergency foil blankets and vacuum flasks.
- The detector/sensor must be kept at the SAME fixed distance from each face for a fair comparison.
- All faces must start at the SAME temperature — otherwise a hotter face would simply emit more anyway, for reasons unrelated to its surface.
Common exam question types
- Rank surfaces by how much infrared radiation they emit/absorb, and explain the pattern.
- Explain why the cube’s faces must all start at the same temperature.
- Explain a real-world application (e.g. why radiators are often painted a dark colour, or why survival blankets are shiny).