Corrections log
Mistakes get into study material. What matters is finding them and saying so. This page lists every correction we have made, newest first, with the date and what was wrong.
Most of these were found by re-checking our own work: re-solving every calculation by hand, re-deriving every practice-question answer and every wrong-option explanation, and testing each NCERT citation against the page it cites. The reference next to each entry is the change record it comes from.
Found something wrong? Tell us and it will be fixed and listed here.
26 September 2026
Past-paper questions
A 2024 physics question (question 48: the magnetic moment of a bar magnet bent to a 60° angle) showed “2” as the correct answer. Text extraction had flattened the fractions in its options, so they read “M M”, “2”, “2M M” and “3”. They now read M, M/2, 2M and M/√3, as printed, and NTA's answer, M/2, shows as correct. In a 2024 chemistry question (question 68, on the energy of an electron in Be³⁺) the page number had become part of one option; it is fixed from the paper too. Both were found by a new check that compares the question and every option on the site with the paper it came from, option by option. It flagged 19 of 1,131 questions. The other 17 were read on their page and are correct: their structures and reaction schemes are drawings, which the paper's text cannot show. No answer key changed. The check now runs before any change to the question bank is accepted.
Ref 175f98a
25 September 2026
Past-paper questions
A 2021 chemistry question (question 96: which pair of ions is not isoelectronic) showed “O²⁻, F⁻” as the correct answer. The first option, “Fe²⁺, Mn²⁺”, had been attached to the end of the question, the other options had moved up one place, and the fourth option read “Answer”. NTA's answer, option (1) Fe²⁺, Mn²⁺, now shows as correct. A search of all 1,160 past-paper questions for the same damage (answer-sheet labels, text from the neighbouring column, options stuck to the question) found 18. 15 were read from their page in the paper and retyped, 2 were correct as printed, and 1 needs its graphs, so it stays hidden. In one of them (2021 question 192, on altitude sickness) all four options had been replaced by rows from another question's matching list, so what showed as the answer was wrong too. One more damaged 2021 question found while checking was fixed. No answer key changed. The site now hides any new question with this damage until it has been read.
Ref 71c14cc
Past-paper questions
The 21 June 2026 re-exam was missing from past-paper practice from 23 September: a rebuild of the question bank dropped 178 of its questions and their 22 redrawn figures. They are back, and the bank is now rebuilt from a source that keeps them. Before restoring them, every answer was checked against NTA's final answer key. Three had been shown with the wrong answer from 18 to 23 September (questions 18, 19 and 27); they now show NTA's answer. Question 48 named the wrong carbocation (benzyl instead of the 1-phenylethyl cation printed in the paper), and question 115 said “sino-arterial” for “sino-atrial”. Both are fixed. Question 26, which NTA dropped, and question 38, where NTA accepts two answers, are not in practice; both are in the re-exam walkthrough.
Ref 38fe1e1
Past-paper questions
14 past-paper questions were hidden because their answer depends on a figure the extracted text could not carry: logic circuits and truth tables, waveforms, a circuit, graphs, and organic ring structures. Each figure was redrawn from the physics or chemistry of the question and checked against the paper page, and each question was solved again from the new figure to confirm it gives the official answer. All 14 are back. Answers were not changed.
Ref 147adb7
NCERT citations
The parallel and perpendicular axes theorems now have an NCERT page again. NCERT removed them from the current Class 11 book in 2023, but NEET still examines them, so we added the last edition that taught them (Class 11 Physics, 2022-23 reprint) to our sources and cite it directly: the perpendicular axes theorem on page 165, the parallel axes theorem on page 167 of that edition's Chapter 7.
Ref 42b0869
Past-paper questions
All 219 Chemistry past-paper questions were read one by one against the syllabus. 91 were under the wrong lesson and were moved (for example a Bravais-lattice question sat under Molecular Orbital theory, and a heat-of-formation question under Markovnikov's rule). 10 that had no lesson now have one. 20 test topics no longer in the syllabus (solid state, surface chemistry, polymers, metallurgy and others) and no longer sit under a lesson. 46 Chemistry questions that had never been added are now on the site: 44 from the 2020 paper and 2 from 2022. 5 questions filed under Chemistry or Physics were Biology and have been moved there. Answers were not changed.
Ref 7ab45ef
Past-paper questions
The remaining 332 Biology past-paper questions were checked one by one for the lesson they appear under, so all 484 have now been read. 118 more were moved, for example gene-mapping and meiosis questions that sat under Nucleus and Chromosomes, conservation questions under Breathing, and contraception under Photosynthesis. Across both passes, 192 of 484 (40%) had been under the wrong lesson. 10 questions on topics no longer in the syllabus (mineral nutrition, digestion, animal husbandry) no longer appear on unrelated lessons. Answers were not changed.
Ref 7b9a08b
Past-paper questions
74 past-paper questions on the site had pieces of their formulas and fractions knocked loose by text extraction: “NH , AlCl , BeCl : 3 3 2”, options reading “InI > InI”, or the same “B k T” four times. A search of all 951 questions found 108 with this kind of damage. 94 were read from their page in the paper and retyped (“NH₃, AlCl₃, BeCl₂”, “√2 : 1”, “dN/dt = rN((K − N)/K)”). 14 need a circuit, graph or structure drawing that text cannot carry, so they stay hidden. Answers were not changed. The site now hides any new question with this damage until it has been read.
Ref 0ad769a
NCERT citations
Four physics lessons cited an NCERT page for the parallel and perpendicular axes theorems. NCERT removed those theorems from the current Class 11 book in 2023; they are still in the NEET 2026 syllabus, and the lessons now say so instead of citing a page. The moment-of-inertia table was cited to page 101; it is on page 116. The Atwood-machine lesson cited a page that does not carry its tension formula, and claimed the tension is less than both weights; it lies between them. Fixed, with the formula now derived step by step.
Ref 6aaa4b1
Past-paper questions
74 Biology past-paper questions were shown under the wrong lesson. They were read one by one and moved. 43 belonged to syllabus topics that had no lesson yet (for example a question on the scapula and sternum sat under Chordates, and one on parathyroid hormone sat under Carbohydrates and Lipids). Those topics now have lessons. 31 were plain mis-tags, such as a brown-algae question under Cytoskeleton. Answers were not changed.
Ref f90789d
Past-paper questions
36 of the 37 past-paper questions hidden for damaged text are back. Each was read from its page in the paper and retyped with real superscripts, subscripts and fractions (“6.6 × 10⁹”, “a³b²/(c√d)”, “MnO₄⁻”). Answers were not changed. One stays hidden: its options are truth tables for a circuit that appears only as a figure.
Ref 34cf289
NCERT citations
44 lesson citations that an automatic check could not confirm were read by hand against the NCERT page. 42 citations in 21 lessons pointed to the wrong page and were moved (for example the simple-pendulum period is on page 271, not 268). 2 claims turned out to have no NCERT page at all (the parallel-axes theorem is not in the current Class 11 book); they are listed for a lesson edit rather than given a page.
Ref fb4b5c4
NCERT citations
Class 11 Chemistry Chapter 8 (Organic Chemistry: Some Basic Principles) could not be checked automatically because its PDF text is unreadable. All 131 citations into it were read against images of the printed pages: 28 pointed one section early (for example the electromeric effect is on page 277, not 275) and were moved.
Ref 352148c
Past-paper questions
18 past-paper questions were shown with their layout broken by text extraction: fractions, reaction schemes, truth tables and subscripts that came out as loose letters. They are hidden until their text is fixed against the official papers.
Ref 97d7fb9
Past-paper questions
On the practice page, 772 of 864 past-paper questions gave their NCERT source as an internal PDF page number (“p. 8”) instead of the page printed in the book (“p. 330”). Fixed, with a check that compares what the live site serves against the source data.
Ref 5ce53f9
Site
About 250 lessons named the wrong NCERT chapter in their “Source” line: a stale copy of the unit-name table was baked into the build. Fixed, with a test that runs the same path the live site takes.
Ref 180b026
Site
All 523 lesson links on the chapters page led to missing pages. Fixed, with a test that checks every link against the real routes.
Ref 180b026
Past-paper questions
Superscripts lost when the papers were extracted (“× 10–8”, “mol–1”, “[MLT–2A–2]”) restored in 131 places. 19 questions whose exponent lost its sign too (“6.6 × 109”) are hidden until their text is fixed against the official paper, rather than shown with a guessed exponent.
Ref 766b143
Practice questions
Physics, third re-derivation pass: 175 questions flagged, 173 fixed; 2 flags rejected because NCERT supports the question as written.
Ref 92296a6, 1413cd5, 41bde4e, 0795517
Practice questions
Chemistry, third re-derivation pass: 80 more defects fixed on 68 questions that two earlier passes had missed.
Ref e942721
Practice questions
Biology: two re-derivation passes fixed 18 questions; a third pass over the conceptual questions fixed 13 more defects.
Ref 5f215f8, 91f7891
24 September 2026
Past-paper questions
18 stored past-paper answers corrected to match the official answer key each record cites; 5 of them were in the question set served on the site.
Ref 318800d
Practice questions
21 questions whose keyed option was not the correct answer: 6 had the key on the wrong option, the rest had no correct option or two.
Ref fdda156
Practice questions
30 physics explanations with false working fixed, and 41 explanations that referred to the wrong option letter.
Ref 2482b84
Practice questions
Chemistry: one wrong answer key and one question with two correct answers fixed; then 42 flagged questions fixed and 12 more defects found alongside.
Ref cf9e281, dde0cd3
Practice questions
24 ambiguous questions rewritten to have exactly one defensible answer, and 6 more in physics.
Ref 0248efe, 05cb37b
Practice questions
325 wrong-option explanations named a letter that was not the option they sat under (“A is wrong because…” beneath option B). All fixed, and the check that should have caught them repaired.
Ref 0214dd2
Worked examples
All 302 numeric worked examples re-solved step by step, separately from the original draft. No arithmetic error found; 6 defects in the surrounding material fixed.
Ref e53ee50
Worked examples
20 worked-example defects fixed: 11 in organic chemistry and 9 found by a six-agent audit (some wrong by a power of ten), each re-derived by hand.
Ref 72810c2, c0fbb90
Practice questions
8 inorganic-chemistry and biology defects fixed; the three biology ones were settled against the NCERT text.
Ref a9a5d94
NCERT citations
88 citations that pointed at an outdated chapter fixed, 34 citations to the wrong subject's book fixed, and 24 citations moved to the page that actually carries the claim.
Ref 0248efe, c0fbb90, 3bda75a
NCERT citations
A citation audit across all 50 units found and fixed 21 defects.
Ref b5ea48e
22 September 2026
Syllabus
13 biology lessons taken off the site: read against the NMC NEET UG 2026 syllabus, their topics are not examined.
Ref a74750b
NCERT citations
445 biology citations moved onto the page that carries the claim.
Ref a0fd9c6
20 September 2026
NCERT citations
The table that maps chapters to printed page numbers was wrong for 9 of 75 chapters; every citation is checked against it. Fixed.
Ref 4729f7e