OAT Physics common mistakes
OAT Physics · Understand the traps and how to avoid them.
Solving every physics problem with the same algebra-first reflex: writing an equation, then hunting for a number to plug in, without first identifying the physical principle and the target quantity. This shows up as choosing v = v0 + at for a problem that actually requires energy conservation, or as stacking kinematics equations on a collision problem.
Undergraduate physics courses reward formula recall under time pressure, so candidates rehearse equation sheets rather than a principle-identification step. The OAT Physics section mixes mechanics, fluids, thermodynamics, optics, and electricity in quick succession, so the reflex trained on one topic misfires on the next.
What to do instead
Before any algebra, write two lines on scratch paper: the principle (e.g., 'conservation of mechanical energy') and the unknown with its units. Then select the equation that contains exactly that unknown plus knowns. Practice by sorting a set of 30 mixed problems into principle categories without solving them, then solve only after the sort is correct.
Treating the OAT as recall-only and skipping dimensional analysis and limiting-case checks, so sign errors and unit slips survive into the chosen answer. Typical concrete behaviors: reporting work in newtons, leaving a projectile time negative, or accepting a refractive index below 1.
Under a timed computerized test, candidates feel that checking is wasted time, and many never built the habit because course exams gave partial credit. The OAT is multiple choice, so a wrong sign usually maps to a distractor that looks plausible.
What to do instead
Adopt a ten-second audit on every physics item: check units of the final answer, check the sign against the physical situation, and test one limiting case (set a variable to zero or infinity and ask whether the answer still makes sense). Do this on practice sets until it is automatic, and track how many errors the audit catches.
Reading the passage first and then trying to hold it in memory while answering, or conversely reading questions first and skim-searching without building the passage's structure. Both produce repeated re-reading and time overruns in Reading Comprehension.
The section is passage-based with several questions per passage, and candidates carry over habits from content sections where memorization is the point. Without an explicit strategy, working memory fills with detail and the main argument gets lost.
What to do instead
Use a fixed two-pass routine: read the passage once at moderate speed, writing a three-to-five-word margin label for each paragraph (function, not content), then answer questions by returning to the labeled location. Practice with a timer until a passage plus its questions takes a consistent, planned number of minutes.
Confusing the question stem's scope in Reading Comprehension: choosing a true statement from the passage when the stem asks for the author's main point, the function of a paragraph, or an inference that must be supported. Also selecting answers that import outside knowledge not stated in the passage.
Distractors are deliberately built from accurate passage details, so a true-but-irrelevant option feels safe. Candidates also default to prior science knowledge because the passages are often scientific.
What to do instead
Before looking at options, phrase the answer in your own words. Then eliminate any option that is true but does not answer the specific stem, and any option that requires information absent from the passage. For inference items, require an explicit textual hook for the chosen answer.
Rushing quantitative reasoning by estimating loosely and then selecting the nearest-looking choice, without checking whether the choices are close together. Concrete behavior: computing 47/0.19 as roughly 200 and picking 200 when the options are 198, 247, 251, and 260.
The section rewards speed, so candidates over-apply approximation and under-apply arithmetic discipline. When answer choices are tightly spaced, rough estimation cannot discriminate among them.
What to do instead
First scan the answer choices. If they are widely separated, estimate; if they are within a few percent, compute exactly or use a ratio trick. Practice a set where the same problem appears with wide and narrow options to build the discrimination habit.
Setting up word problems with the wrong base or the wrong direction: percent increase applied to the new value instead of the original, average speed computed as the arithmetic mean of two speeds, or rates combined additively when they should combine as reciprocals (work and dilution problems).
Everyday language ('average speed', '20% faster') does not match the formal definitions, and candidates translate phrases directly into operations. These traps are standard because they are reliably tempting.
What to do instead
Write the defining relationship before substituting: average speed equals total distance over total time; percent change equals difference over original; combined work rate equals the sum of reciprocal times. Memorize these three definitions as sentences, then drill mixed word problems where the naive operation is one of the distractors.
In General Chemistry calculation items, plugging numbers into a formula without first converting to consistent units and without tracking limiting reactant, so the answer is off by a factor tied to milliliters versus liters, grams versus moles, or kilojoules versus joules. A frequent concrete case is using molarity times volume in milliliters for a mole calculation.
Stoichiometry and solution problems combine several conversions, and candidates who learned the formulas procedurally skip the unit ledger. Under time pressure, the conversion step is the first to be dropped.
What to do instead
Use a dimensional-analysis chain for every calculation, canceling units explicitly and writing the target unit at the end. For reaction problems, always compute moles of each reactant and identify the limiting reagent before using any product ratio. Verify by checking that the final unit matches what the question asks for.
In Organic Chemistry, memorizing named reactions as isolated flashcards and then failing to apply them to an unfamiliar substrate: predicting the wrong major product because stereochemistry, regiochemistry (Markovnikov versus anti-Markovnikov), or a rearranged carbocation intermediate was ignored.
Reaction recall is easier to drill than mechanism reasoning, so study time goes to names and reagents. Exam items test mechanism logic, which requires connecting electron flow to outcome.
What to do instead
For each reaction class, draw the mechanism once from scratch and annotate the regiochemical and stereochemical rule it produces. Then practice predicting products for substrates you have not seen, stating the rule that decided the outcome. Build a one-page map organized by intermediate type (carbocation, carbanion, radical) rather than by reaction name.
In Biology, answering from general knowledge or 'common sense' rather than from the specific mechanism the item tests, producing plausible but wrong choices on cell transport, membrane potentials, or enzyme kinetics. A concrete pattern is calling facilitated diffusion 'active' because it uses a protein, or ignoring that a competitive inhibitor raises Km without changing Vmax.
Biology is the largest content area and feels familiar, so candidates skim stems and rely on gist. Many mechanisms have intuitive-sounding but incorrect variants that make good distractors.
What to do instead
For mechanism-heavy topics, build comparison tables (simple versus facilitated diffusion versus active transport; competitive versus noncompetitive inhibition) with the discriminating feature in one column. On practice items, justify the choice by naming the mechanism, not by familiarity, and review every wrong option to state why it fails.
Managing time and stamina poorly across the full test: spending too long on a few hard items, leaving later sections compressed, and taking no full-length timed practice under test-like conditions. Concrete behavior: never having completed a full-length simulation before test day, then running out of time in the final sections.
Section-level practice does not build pacing or endurance, and candidates underestimate how fatigue degrades accuracy in later sections. Without a timing plan, hard items absorb disproportionate minutes.
What to do instead
Take at least two full-length timed practice tests under realistic conditions and log time per section. Set a per-item cap (mark and move on when exceeded), and rehearse a deliberate guess-and-flag routine so no item consumes the budget of three. Use the log to identify which section needs pacing work, not just content review.