These descriptions explain mistakes Keiko's questions were written to distinguish. The counts describe this bank's authored distractors. They do not measure student performance or prescribe how to divide your study time. Independent specialist and outcome validation remain pending.
GRE Physics
823 items in this bank carry named causes on their wrong answers, covering 3,062 wrong answers between them and drawing on 31 of the 84 named errors. 18 of those errors appear nowhere else: they are the ones that are about physics rather than about reading a question. They are set out below, grouped by the content area each one turns up in most. The other 13 are the cross-exam errors listed under errors that are not about the subject.
power_law_exponent_droppedThe quantity was rescaled by the raw factor even though the physical law raises that factor to a power or takes its root.
Write the law as a power relation first, then apply the change to that power rather than to the quantity itself. Halving a radius rarely halves anything.
134 wrong answers written to catch it, 57 of them in classical mechanics · wrong method
reciprocal_reportedThe physics is right but the final ratio was inverted, so the answer is one over the value the prompt requested.
Read the ratio in the order the prompt states it, and check the answer falls on the side of one you expect.
96 wrong answers written to catch it, 25 of them in classical mechanics · calculation or execution error
conservation_law_violatedThe selected outcome does not conserve the quantity that is conserved under the stated conditions.
List the quantities that are conserved under the stated conditions, then discard every option that breaks one. This eliminates faster than computing does.
33 wrong answers written to catch it, 15 of them in classical mechanics · concept gap
mass_distribution_misjudgedThe chosen answer ignores how far the mass lies from the rotation axis, which is what sets the moment of inertia.
Ask where the mass sits relative to the axis. Rotation is governed by distance squared, so moving mass outward matters more than adding it near the centre.
11 wrong answers written to catch it · concept gap
vector_product_direction_confusedThe magnitude is handled but the direction that a cross product fixes was taken along the wrong axis or sign.
Redo the right-hand rule with the vectors in the order the definition gives them, then check the sign of the result against a case you already know.
16 wrong answers written to catch it · concept gap
propagation_aligned_with_fieldThe chosen direction is that of the electric or magnetic field rather than the propagation direction they jointly define.
Take the two field directions first. The wave travels along the direction their cross product defines, which is neither of them.
9 wrong answers written to catch it · concept gap
unaffected_quantity_treated_as_changingThe chosen answer scales a quantity that the described change does not touch, which is the mirror image of ignoring a real dependence.
List what the described change actually touches and hold everything else fixed. Scaling a quantity the setup never altered is as wrong as ignoring one it did.
11 wrong answers written to catch it, 6 of them in electromagnetism · concept gap
cross_product_angle_misusedThe sine factor in a magnetic force law was evaluated as though the angle between the vectors were different.
Identify which two vectors the angle sits between, and evaluate the sine factor from that angle alone. The angle to a third direction is not the one in the law.
9 wrong answers written to catch it, 6 of them in electromagnetism · wrong method
series_parallel_swappedThe combination rule for the other wiring topology was used for this circuit.
Decide series or parallel from what the current is free to do, not from how the diagram happens to be drawn on the page.
8 wrong answers written to catch it, 6 of them in electromagnetism · wrong method
rate_confused_with_valueThe chosen answer tracks how large a quantity is when the law depends on how fast that quantity is changing.
Ask whether the law depends on how large the quantity is or on how fast it is changing, and read the graph or the description for that one thing.
8 wrong answers written to catch it, 5 of them in electromagnetism · concept gap
available_states_miscountedThe counting rule for allowed quantum numbers, degenerate states, nodes, or active degrees of freedom was applied incorrectly.
Rebuild the count from the rule that generates the states — allowed quantum numbers, nodes, active degrees of freedom — instead of recalling a total.
78 wrong answers written to catch it, 34 of them in quantum mechanics · concept gap
limit_case_overextendedA real effect was taken to an extreme the stated conditions never reach.
Work out how far the stated conditions actually push the effect before you treat it as an extreme. Real effects have sizes, and most of them are small here.
109 wrong answers written to catch it, 22 of them in quantum mechanics · concept gap
intensity_confused_with_photon_energyThe chosen answer makes intensity change a per-photon property that only frequency controls.
Separate how many photons arrive from how much energy each one carries. Brightness changes the first; only frequency changes the second.
2 wrong answers written to catch it · concept gap
arithmetic_slipThe formula and the substituted givens are right; the number that came out of the division, multiplication, or rounding is not.
Re-run the final arithmetic once with rounded numbers and check the order of magnitude. This catches the slip without costing a second full calculation.
211 wrong answers written to catch it, 53 of them in thermodynamics · calculation or execution error
second_law_direction_ignoredThe chosen answer moves heat or entropy in a direction that is forbidden without work input.
Check the direction of heat flow and the sign of the entropy change before accepting an outcome. Without work going in, heat does not run uphill.
20 wrong answers written to catch it · concept gap
absolute_temperature_not_usedA gas or radiation law that is written in absolute temperature was evaluated with a Celsius value, so the ratio comes out wrong.
Convert every temperature to kelvin before it enters a law written in absolute temperature. A ratio of Celsius readings is not a ratio of temperatures.
4 wrong answers written to catch it · wrong method
lattice_type_confusedThe number quoted belongs to another cubic lattice type than the one named in the prompt.
Name the lattice in the prompt and recount its atoms per cell for that lattice. The three cubic cells give three different counts, and they are easy to blur together.
11 wrong answers written to catch it · concept gap
galilean_addition_usedRelative speeds were combined by ordinary addition or subtraction instead of the relativistic rule, which can even push the result past c.
Combine relative speeds with the relativistic rule whenever either is a serious fraction of the speed of light, and check that the result stays below it.
18 wrong answers written to catch it · wrong method
The same 13 errors that appear in all three subject tests, counted inside GRE Physics alone.
| Named error | Wrong answers in GRE Physics |
|---|---|
| Reached for a neighbouring definition | 410 |
| Used the relationship in the wrong direction | 259 |
| Right method, wrong power | 255 |
| Treated the result as independent of the change | 220 |
| Applied the version of the rule that fits a different case | 157 |
| Combined the quantities with the wrong rule | 149 |
| Left a factor out of the formula | 142 |
| Dropped a condition the problem stated | 141 |
| Reported a different quantity than the one asked for | 139 |
| Substituted the wrong given | 127 |
| Lost or flipped a sign | 107 |
| Leaned on a quantity that does not enter | 97 |
| Stopped at an intermediate result | 71 |
GRE Physics Subject Test study hub — the syllabus, the free study notes, and the practice these items belong to.