Strategy, PYQs & predictions
Exam strategy, previous-year analysis, and how the prediction engine actually works.
Laws of Motion JEE 2019: Quadratic Drag Ball Problem
Complete walkthrough of the 2019 JEE Main Laws of Motion quadratic drag question showing why the time to highest point requires the arctan form and not the logarithmic expression.
Founder, JEEnius - IIT Kanpur Alumni · Sep 8, 2026 · 3 min read
Solutions JEE 2022: Vapour Pressure Numerical Yields 5 Ions
Official solutions JEE 2022 for the JEE Advanced relative lowering of vapour pressure numerical explained with the correct van't Hoff factor setup that gives N exactly 5.
Founder, JEEnius - IIT Kanpur Alumni · Sep 7, 2026 · 4 min read
Reflection and Refraction JEE 2019: Concave Mirror in Water
The 2019 JEE Main question combining reflection and refraction with a concave mirror at the bottom of water is solved in detail with the official 8.8 cm answer and common pitfalls.
Founder, JEEnius - IIT Kanpur Alumni · Sep 7, 2026 · 3 min read
Limit, Continuity and Differentiability JEE 2013: f(x) < 0 on (0,1)
Breakdown of the JEE Advanced 2013 paragraph question from the limit, continuity and differentiability chapter that uses strict convexity to prove f must be negative on (0,1).
Founder, JEEnius - IIT Kanpur Alumni · Sep 6, 2026 · 3 min read
P-Block Elements JEE 2022: Blast Furnace Question Analysis
The official solution and common mistakes for the JEE Advanced 2022 blast furnace question at 900-1500 K with key facts on pig iron, slag and exhaust gases every aspirant must know.
Founder, JEEnius - IIT Kanpur Alumni · Sep 6, 2026 · 4 min read
Moment of Inertia JEE 2019: Variable Density Plate
Detailed solution to the 2019 JEE Main hard question on moment of inertia of a variable-density circular plate with ρ(r)=ρ₀r, showing all integration steps, parallel axis shift and common algebraic errors.
Founder, JEEnius - IIT Kanpur Alumni · Sep 6, 2026 · 3 min read
Equilibrium JEE 2022 Empirical Formulae Multi-Correct Solution
Senior faculty breaks down the Equilibrium JEE 2022 multi-correct stoichiometry question on empirical formulae of P and Q with official calculations, correct options B and C, and the key ratio mistake.
Founder, JEEnius - IIT Kanpur Alumni · Sep 5, 2026 · 5 min read
Photoelectric Effect JEE 2019: Superposed Magnetic Field Solution
Official step-by-step solution to the JEE Main 2019 photoelectric effect question featuring superposed magnetic fields, showing exactly how to extract frequencies and compute K_max = 7.675 eV.
Founder, JEEnius - IIT Kanpur Alumni · Sep 5, 2026 · 3 min read
Integral Calculus JEE 2014: Solving (2 Cosec x)^17
Detailed solution to the JEE Advanced 2014 integral of (2 cosec x)^17 using exponential substitution, binomial theorem and hyperbolic recurrence relations.
Founder, JEEnius - IIT Kanpur Alumni · Sep 4, 2026 · 3 min read
Redox Reactions and Electrochemistry JEE 2022: Entropy MCQ Solution
Senior faculty breaks down the JEE Advanced 2022 multi-correct entropy question from redox reactions and electrochemistry with official solution, common mistakes and practice problems.
Founder, JEEnius - IIT Kanpur Alumni · Sep 4, 2026 · 4 min read
The P-Block Elements JEE 2022: Why PbCl2 Dissolves in HCl
Official JEE Advanced 2022 solution for the p-block PbCl2 dissolution in HCl via [PbCl4]2- complex formation, including equilibrium shift, common mistakes and practice questions.
Founder, JEEnius - IIT Kanpur Alumni · Sep 3, 2026 · 3 min read
Capacitance JEE 2020: Inclined Plates Solution
Step-by-step solution to the JEE Main 2020 capacitance question on square plates tilted at small angle α, showing mandatory integration, logarithmic approximation and common arithmetic-mean mistake.
Founder, JEEnius - IIT Kanpur Alumni · Sep 3, 2026 · 4 min read
P-Block Elements JEE 2021: Metallurgy Question Solution
Senior faculty breaks down the 2021 JEE Advanced p-block elements metallurgy multi-correct question with exact balanced equations, common traps and must-memorise reactions.
Founder, JEEnius - IIT Kanpur Alumni · Sep 2, 2026 · 5 min read
Moment of Inertia JEE 2020: Equilateral Triangle Numerical
Step-by-step official solution to the JEE Main 2020 moment of inertia numerical on equilateral triangular lamina after removing smaller triangle ADE, yielding N=11.
Founder, JEEnius - IIT Kanpur Alumni · Sep 2, 2026 · 3 min read
Mixed Mathematics JEE 2015: Official Matrix Match Solution
Official step-by-step solution to the mixed mathematics JEE 2015 matrix match with correct matching, the common algebraic error in part A, and targeted practice on trigonometry, vectors and areas.
Founder, JEEnius - IIT Kanpur Alumni · Sep 1, 2026 · 4 min read
Work, Energy and Power JEE 2021: Bullet Pendulum Problem
This article breaks down the Work, Energy and Power JEE 2021 bullet and pendulum problem, providing the official solution for minimum velocity of 400 m/s and explaining common mistakes.
Founder, JEEnius - IIT Kanpur Alumni · Sep 1, 2026 · 4 min read
Limit, Continuity and Differentiability JEE 2015 Official Solution
Breakdown of the JEE Advanced 2015 differentiability question with f and h shows only f and h(f(x)) are differentiable at x=0 by computing one-sided derivatives and avoiding common chain-rule errors.
Founder, JEEnius - IIT Kanpur Alumni · Aug 31, 2026 · 4 min read
Redox Reactions and Electrochemistry JEE 2021: Nernst Equation
Detailed solution to the JEE Advanced 2021 multi-correct question on Nernst equation from redox reactions and electrochemistry explaining when E_cell stays positive.
Founder, JEEnius - IIT Kanpur Alumni · Aug 31, 2026 · 4 min read
Vector Algebra JEE 2021: Why Both Statements Are False
Senior faculty breaks down the vector algebra JEE 2021 PYQ on P+Q and P-Q resultants to show exactly why both statements are false using the official simplification and derived cosines.
Founder, JEEnius - IIT Kanpur Alumni · Aug 31, 2026 · 4 min read
Coordinate Geometry JEE 2015: Common Tangent to Ellipses
Official 2015 JEE Advanced solution for two ellipses with common tangent x+y=3, coefficient matching for eccentricities, axis identification errors and reusable template.
Founder, JEEnius - IIT Kanpur Alumni · Aug 30, 2026 · 3 min read
Laws of Motion JEE 2022: Hard Projectile Momentum Vector
Complete solution to the hard JEE Main 2022 projectile momentum vector question tagged under laws of motion, with NTA method, trig error analysis and linked conservation of momentum PYQs.
Founder, JEEnius - IIT Kanpur Alumni · Aug 29, 2026 · 3 min read
Limit, Continuity and Differentiability JEE 2016: Official Solution
Analysis of the JEE Advanced 2016 limit, continuity and differentiability question with detailed steps to arrive at f'(x)/f(x) and evaluate the multiple correct options.
Founder, JEEnius - IIT Kanpur Alumni · Aug 29, 2026 · 3 min read
Oxoacids of Phosphorus JEE 2021: Official Multi-Correct Solution
Official walkthrough of the 2021 JEE Advanced multi-correct question on oxoacids of phosphorus, using the HPO(OH)2 structure of H3PO3 to evaluate every statement on disproportionation, reducing character and basicity.
Founder, JEEnius - IIT Kanpur Alumni · Aug 29, 2026 · 4 min read
Limit, Continuity and Differentiability JEE 2018: Official Solution
Complete breakdown of the 2018 JEE Advanced twice differentiable function question testing limit, continuity and differentiability with full solutions, counterexamples and practice problems using MVT and auxiliary functions.
Founder, JEEnius - IIT Kanpur Alumni · Aug 28, 2026 · 4 min read
Hydrocarbons JEE 2021: Solving the BDE Matching Question
Breakdown of the JEE Advanced 2021 hydrocarbons BDE matching question with radical stability ladder, official solution, common mistakes and targeted practice problems.
Founder, JEEnius - IIT Kanpur Alumni · Aug 28, 2026 · 4 min read
Atomic Structure JEE 2021: Helium Atom Recoil Velocity
Official step-by-step solution for the JEE Advanced 2021 helium atom recoil numerical in atomic structure using momentum conservation, with common mistakes and practice questions.
Founder, JEEnius - IIT Kanpur Alumni · Aug 27, 2026 · 3 min read
Circle JEE 2018: Deriving E1 and E2 Loci
Complete breakdown of the Circle JEE 2018 loci question with equations, exclusions, option analysis and similar practice problems for JEE Advanced.
Founder, JEEnius - IIT Kanpur Alumni · Aug 26, 2026 · 3 min read
The p-Block Elements JEE 2021: Oxidation State of Cl in Cl2O6
Official step-by-step solution to the JEE Advanced 2021 p-block numerical on average oxidation state of chlorine in Cl2O6, the balanced equation, common +7 mistake, and similar questions.
Founder, JEEnius - IIT Kanpur Alumni · Aug 26, 2026 · 3 min read
Differential Equations JEE 2018: Official Solution and Analysis
Senior faculty solves the differential equations JEE 2018 question from JEE Advanced, derives f(x)=-x sin x using L'Hospital and quotient rule, exposes the sign error that flips answers, proves all statements with derivatives, and supplies two matching practice problems.
Founder, JEEnius - IIT Kanpur Alumni · Aug 24, 2026 · 5 min read
Vector Algebra JEE 2024: Minimum of 27|c − a|^2
Senior faculty solves the JEE Main 2024 vector algebra question on a = b × c with angle in [0, π/3], proving the minimum of 27|c-a|^2 is 124 and explaining common pitfalls.
Founder, JEEnius - IIT Kanpur Alumni · Aug 24, 2026 · 3 min read
Trigonometric Functions JEE 2025: Inverse Equation Has Three Solutions
Senior faculty analyses the JEE Advanced trigonometric functions jee 2025 inverse equation, proving it has exactly three real solutions and highlighting key mistakes and identities to master before the exam.
Founder, JEEnius - IIT Kanpur Alumni · Aug 23, 2026 · 3 min read
Gravitation JEE 2024: h/H = 1/2 Maximises Total Time
Detailed breakdown of the JEE Main 2024 gravitation question that involves finding the height ratio h/H to maximise the total time to reach the ground after an elastic collision with a 45 degree inclined plane.
Founder, JEEnius - IIT Kanpur Alumni · Aug 23, 2026 · 4 min read
Electric Field JEE 2024 Numerical: Sheet and Line Charge
Complete breakdown of the hard electric field JEE 2024 numerical on infinite sheet and line charge superposition that yields n=16, with steps, mistakes and geometry explained.
Founder, JEEnius - IIT Kanpur Alumni · Aug 22, 2026 · 4 min read
Matrices and Determinants JEE 2020: Adjoint of Adjoint Question
Complete breakdown of the hard JEE Advanced 2020 multi-correct question on adjoint of adjoint for 3x3 matrices, including full derivation, why A is wrong and targeted practice problems.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 3 min read
Limit, Continuity and Differentiability JEE 2020 Question Solution
Official step-by-step solution to the JEE Advanced 2020 functional equation question that uses the limit of g(x) to prove continuity, differentiability of f and g, and derive the explicit form f(x)=e^x-1.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
P-Block Elements JEE 2010: Matrix Match on Halide Hydrolysis
Senior faculty explains the 2010 JEE Advanced p-block elements matrix match with full hydrolysis equations, oxidation states, secondary reactions, common mistakes and targeted practice questions.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Matrices and Determinants JEE 2022: HP Consistency Match List
See the official solution to the JEE Advanced 2022 match list question from matrices and determinants involving HP terms p, q, r and why p/q = 10 is the key condition for infinite solutions.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Thermodynamics JEE 2020: Diathermic Partition Ambiguity
JEE Advanced 2020 thermodynamics question on movable diathermic partition was ambiguous because it omitted CV, leading to no unique x and bonus marks for all candidates.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Organic Compounds Containing Oxygen JEE 2020: Degree of Unsaturation
Detailed solution to the JEE Advanced 2020 numerical on degree of unsaturation for the cyclised product Q from organic compounds containing oxygen, showing atom-by-atom formula derivation and common errors.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 3 min read
Thermodynamics JEE 2022: Soap Bubble Multi-Correct Question
Complete breakdown and official solution of the JEE Advanced 2022 Paper 2 multi-correct soap bubble thermodynamics question for insulating and conducting surfaces.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Some Basic Principles JEE 2022: Benzene Succinic Anhydride Sequence
Breakdown of the JEE Advanced 2022 benzene succinic anhydride question that tested Some Basic Principles of Organic Chemistry including selective reductions, intramolecular acylation and precise carbonyl reactivity.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Electrostatics JEE 2022: Charged Disk with Constant Force
Senior faculty explains the JEE Advanced 2022 electrostatics question on a charged particle above a uniformly charged disk with added constant force, using effective potential u(x) to determine particle motion and correct options.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Chemical Bonding JEE 2026: 6 Paramagnetic Complexes Numerical
Complete solution to the JEE Main 8 April 2026 chemical bonding numerical showing exactly 6 paramagnetic complexes using the official 4-step decision tree on oxidation state, geometry, ligand strength and spin.
Founder, JEEnius - IIT Kanpur Alumni · Aug 21, 2026 · 4 min read
Complex Numbers and Quadratic JEE 2020: Set S Analysis
Detailed breakdown of the JEE Advanced 2020 multi-correct question on the set S defined by |z² + z + 1| = 1, with locus explanation, official proofs for options B and C, common algebraic mistakes, and similar problems.
Founder, JEEnius - IIT Kanpur Alumni · Aug 20, 2026 · 5 min read
Kinetic Theory of Gases JEE 2017: Moving Plate in Rarefied Gas
Senior faculty breaks down the 2017 JEE Advanced kinetic theory of gases question on a plate in rarefied gas, with official derivations, correct options A B D, common mistakes and similar practice problems.
Founder, JEEnius - IIT Kanpur Alumni · Aug 19, 2026 · 3 min read
Integral Calculus JEE 2022: Why the Correct Answer Is C and D
This worked solution reduces the integral to a parameter function, counts one root on each domain interval and proves both roots irrational.
Founder, JEEnius - IIT Kanpur Alumni · Aug 17, 2026 · 5 min read
Redox Reactions and Electrochemistry JEE 2013: Full Solution
A worked solution to the 2013 match-list problem, showing why electrode potentials must be combined through Gibbs energy.
Founder, JEEnius - IIT Kanpur Alumni · Aug 17, 2026 · 6 min read
Work, Energy and Power JEE 2018: Match-List Solution
A derivative-based solution to the 2018 JEE Advanced match-list problem on momentum, torque, kinetic energy, potential energy and total energy.
Founder, JEEnius - IIT Kanpur Alumni · Aug 17, 2026 · 6 min read
JEE Main Mock Test Analysis: A 7-Step Error Audit
Turn every wrong, lucky or unattempted question into a ranked repair task and three rules for the next JEE Main mock.
Founder, JEEnius - IIT Kanpur Alumni · Aug 17, 2026 · 10 min read
Organic Compounds Containing Oxygen JEE 2014: Answer 5
Enumerate all ketones of mass 100, account for existing stereocentres and see why the correct integer is 5.
Founder, JEEnius - IIT Kanpur Alumni · Aug 16, 2026 · 5 min read
Gravitation JEE 2025: Mass Transfer and Orbital Expansion
This solution derives the orbital expansion rate using force balance, angular momentum conservation and logarithmic differentiation.
Founder, JEEnius - IIT Kanpur Alumni · Aug 16, 2026 · 5 min read
JEE Chemistry Important Chapters: Best Order and 8-Week Plan
Build Chemistry in dependency order, then use recent question frequency, timed PYQs and an eight-week schedule to convert priority chapters into marks.
Founder, JEEnius - IIT Kanpur Alumni · Aug 16, 2026 · 11 min read
Best JEE Mock Test App: How to Choose Realistic Mocks
Compare full mocks, chapter-wise apps and coaching series using JEE Main pattern fidelity, test analysis and student stage.
Founder, JEEnius - IIT Kanpur Alumni · Aug 16, 2026 · 8 min read
Some Basic Principles of JEE 2024: Why the Answer Is 2 or 4
A rigorous structural audit shows why this JEE Advanced 2024 organic chemistry numerical legitimately accepts both 2 and 4.
Founder, JEEnius - IIT Kanpur Alumni · Aug 15, 2026 · 4 min read
Some Basic Principles of JEE 2024: Why the Answer Is 2 or 4
A complete structural analysis showing why this JEE Advanced 2024 Chemistry PYQ accepts both 2 and 4.
Founder, JEEnius - IIT Kanpur Alumni · Aug 15, 2026 · 4 min read
Vector Algebra JEE 2022: Solving the Advanced Multi-Correct PYQ
A direct solution to the JEE Advanced 2022 vector algebra PYQ, covering cross-product order, parameter elimination and all four option checks.
Founder, JEEnius - IIT Kanpur Alumni · Aug 14, 2026 · 5 min read
Organic Compounds Containing Oxygen JEE 2025: Answer
Solve the 2025 oxygen-containing organic chemistry numerical using the correct coupling ratio, successive yields and final molar mass.
Founder, JEEnius - IIT Kanpur Alumni · Aug 14, 2026 · 5 min read
Current Electricity JEE 2022: Hard Nodal Analysis
A rigorous nodal-analysis solution to the JEE Advanced 2022 circuit, including battery signs, current directions and power verification.
Founder, JEEnius - IIT Kanpur Alumni · Aug 14, 2026 · 5 min read
JEE Main 1 Year Study Plan for Class 11 Students
Build a sustainable Class 11 JEE Main year with a 23.25-hour weekly timetable, subject allocation, testing phases and backlog rules.
Founder, JEEnius - IIT Kanpur Alumni · Aug 14, 2026 · 11 min read
Matrices and Determinants JEE 2021: Identities and Solution
One inverse relation and Sylvester’s theorem settle the JEE Advanced 2021 matrix question: A, B and C are true; D is false.
Founder, JEEnius - IIT Kanpur Alumni · Aug 13, 2026 · 4 min read
Ray Optics and Optical JEE 2022: Multiple-Reflection PYQ
A coordinate-based solution proving that A and B alone are correct, with the five-reflection path traced exactly.
Founder, JEEnius - IIT Kanpur Alumni · Aug 13, 2026 · 6 min read
Biomolecules JEE 2021: Aldaric Acid Stereochemistry
A rigorous solution to the 2021 aldaric acid PYQ, covering nitric-acid oxidation, Fischer equivalence, enantiomers and why C and D are correct.
Founder, JEEnius - IIT Kanpur Alumni · Aug 10, 2026 · 4 min read
JEE Main 90 Day Strategy: Timetable, PYQs and Mocks
A three-phase JEE Main plan with realistic timetables, chapter triage, PYQs, mocks, error analysis and weekly score tracking.
Founder, JEEnius - IIT Kanpur Alumni · Aug 10, 2026 · 12 min read
Conic Sections JEE 2026: Hard Circle PYQ Solved
A four-step solution to the JEE Main 2026 circle PYQ, covering radius, centre selection, line distance and the chord-square formula.
Founder, JEEnius - IIT Kanpur Alumni · Aug 9, 2026 · 4 min read
AI Doubt Solver for JEE: ChatGPT, Gemini and More
Compare ChatGPT, Gemini, Gauth, Doubtnut and Photomath for JEE doubts, then use a practical checklist to verify every solution.
Founder, JEEnius - IIT Kanpur Alumni · Aug 9, 2026 · 11 min read
JEE Main 30 Day Strategy: Daily Timetable and 7 Mocks
Build the final month around chapter triage, seven analysed mocks, targeted repair, timed PYQs and a controlled three-day taper.
Founder, JEEnius - IIT Kanpur Alumni · Aug 9, 2026 · 14 min read
Pulley Problems JEE: Two-Block Systems and Friction
Learn a fixed Newton's-law method for ideal Atwood machines and rough-table pulley systems, including acceleration, tension and friction checks.
Founder, JEEnius - IIT Kanpur Alumni · Aug 8, 2026 · 8 min read
Pulley Constraint Equations for JEE: String Length, Tension and Friction
Learn a constraint-first method for fixed-pulley, Atwood-machine and rough-table questions, with solved examples and error checks.
Founder, JEEnius - IIT Kanpur Alumni · Aug 5, 2026 · 8 min read