How Lumini helps with A-Level Physics
You're working through an A-Level Physics past paper on your Mac. Question 4 is about a charged particle moving through perpendicular electric and magnetic fields. You need to derive the velocity selector equation, then apply it to a mass spectrometer scenario. You've started the derivation but you're stuck on whether the electric and magnetic forces add or subtract, and whether your sign convention is correct.
Lumini sees your derivation on screen — the forces you've drawn, the equations, your algebraic steps. Hold Ctrl+Option and ask "Is my velocity selector derivation correct?" Lumini checks: "You've correctly identified that the electric force (FE = qE) points upward and the magnetic force (FB = qvB) points downward — they must balance for the particle to travel undeflected. Setting qE = qvB and cancelling q gives v = E/B. That's correct. But check your final line — you wrote v = B/E. That's the reciprocal. I'm pointing at the fraction — you divided the wrong way."
Synoptic questions — connecting topics
A-Level Physics synoptic questions combine multiple topics in one problem. Lumini helps you identify which areas of physics are involved: "This question starts with a mechanics scenario (a mass on a spring), moves into waves (the period of oscillation), and ends with materials (stress-strain for the spring). That's three different topics in one question. You answered the mechanics part correctly but your wave equation uses frequency when the question gives you time period. T = 1/f, so f = 1/T. You should have used T directly in the SHM equation rather than converting to f first. I'm pointing at the time period value in the question — use it directly."
Sign conventions and reference frames
A-Level Physics is unforgiving about sign conventions. Lumini catches these errors: "You calculated the work done by the gas as negative because the gas expands against the atmosphere. But the question asks for the work done ON the gas, which is the negative of the work done BY the gas. You need to flip the sign. The examiner specifically words it this way to test your understanding of sign conventions. I'm pointing at the phrase 'on the gas' vs 'by the gas.'"
For circuit questions: "You've assumed conventional current flows from positive to negative, which is correct for circuit analysis. But the question asks about electron flow — that goes the opposite direction. Don't confuse the two. The ammeter reading is the same regardless because current is a scalar, but if the question asks about electron movement specifically, flip the direction."
Example questions to ask Lumini
- "Is my sign convention correct here?"
- "Which topics are combined in this synoptic question?"
- "Should I use the SUVAT equations or energy conservation for this?"
- "Is my answer reasonable — should it be this large/small?"
- "Am I confusing work done ON vs work done BY?"
How Lumini automates your Physics revision
Say "Create a note with sign conventions for each topic area." Say "Remind me to do Paper 3 with the practical section at 2pm." Say "Search the web for AQA A-Level Physics synoptic question approaches." All on your screen.