Every AQA physics required practical with its key measurement, its main source of error and the fix, then data questions in new contexts.
What you will learn
- Say what each required practical measures
- Name its main source of error and how to reduce it
- Say whether a mistake makes a result too high or too low
- Process and evaluate data from an unfamiliar experiment
Ten practicals, one table
Each practical has its own lesson in its topic unit.
This table puts them side by side for revision.
| Practical | Key measurement | Main source of error | Fix |
|---|---|---|---|
| Specific heat capacity | Temperature rise of a block and energy supplied (joulemeter, or P × t) | Energy lost to the surroundings | Insulate the block; oil in the thermometer hole |
| Thermal insulation (Physics only) | Temperature of cooling water at regular times | Different lids, volumes or start temperatures | Same volume, start temperature and lid each time |
| Resistance of a wire | p.d. and current for each length of wire | Wire heats up, so its resistance rises | Small current; switch off between readings |
| I-V characteristics | Current for a range of p.d.s, both directions | Too few readings where the graph bends | More readings, closer together, near the bend |
| Density | Mass on a balance; volume by measuring or displacement | Parallax at the meniscus; splashes | Eye level with the bottom of the meniscus; lower gently |
| Force and extension | Extension of a spring for each weight added | Parallax when reading the ruler | Pointer on the spring; eye level with it |
| Acceleration | Acceleration of a trolley for different forces or masses (light gates) | Friction; timing by hand | Tilt the runway to cancel friction; light gates |
| Waves | Frequency and wavelength in a ripple tank and on a string | Waves move too fast to measure by eye | Stroboscope or photo; measure across many waves |
| Light (Physics only) | Angles of reflection and refraction against the normal | A wide ray is hard to mark | Narrow slit; two dots far apart along each ray |
| Infrared radiation | Radiation from each face of a hot cube (Leslie cube) | Detector at different distances | Same measured distance from each face |
Edexcel calls these core practicals and OCR groups them in practical activity groups (PAGs). The skills are the same; the exact list differs by board.
The rest of this lesson and its 9 practice questions are locked.
In this lesson
- Ten practicals, one table
- Too high or too low?
- Data you have not seen before
9 practice questions, marked as you go; about 25 minutes in all.
In this unit: Required practicals, maths skills and the equations
The skills every physics paper tests: units and standard form, uncertainty and errors, planning, graphs, the equations and the required practicals side by side.
- Units, prefixes and standard form
- Measurements, uncertainty and errors
- Variables, planning and risk
- Graphs: gradients, intercepts and areas
- The equations: learn, choose and rearrange
- The required practicals side by side
- Equation list B: recall and the formulae sheet
- Equation list C: word equations, recall and the equation sheet