JEE Main Physics Formula Book

JEE Main Physics: Pattern, Strategy, Units, Dimensions and Errors

This chapter does two jobs. It sets out the verified pattern of JEE (Main) 2027 Paper 1 as it affects Physics, maps the twenty NTA Physics units onto the ten chapters of the book, and gives a strategy built around the +4/-1 marking and the five integer-answer questions. It then teaches Unit 1, Units and Measurements, completely, together with the vernier callipers and screw gauge from the Experimental Skills unit. The constants table and the error rules here are used by every later chapter.

KarmSakha preparation topics covered

• Paper 1 pattern, marking scheme and Session 1 schedule for JEE (Main) 2027
• Twenty-unit Physics syllabus map and the 2027 changes
• Expected-value arithmetic for MCQs and integer-answer questions
• SI base units, named derived units and unit conversions
• Master table of physical constants (CODATA 2022)
• Dimensional formulae and the principle of homogeneity
• Uses and limits of dimensional analysis
• Significant figures and rounding rules
• Absolute, relative and percentage error and their combination
• Vernier callipers and screw gauge: least count and zero error

JEE Main 2027 Paper 1: Pattern, Marking and the Physics Share

Paper 1 of JEE (Main) 2027, meant for admission to B.E./B.Tech. programmes, is conducted only as a Computer Based Test. It carries 75 questions and 300 marks, split equally among Mathematics, Physics and Chemistry. Each subject has Section A with 20 multiple-choice questions and Section B with 5 questions whose answers are numerical values, so Physics contributes 25 questions and 100 marks. The duration is 3 hours for every candidate, extended to 4 hours for PwD/PwBD candidates who are eligible for a scribe. Because the three subjects are weighted equally, a formula-heavy subject like Physics is not a side dish: a score of 70 out of 100 in Physics is worth exactly as much as 70 out of 100 in Mathematics.

Marking is symmetrical across both sections. A correct answer earns +4, an incorrect answer costs -1, and an unanswered question or one only marked for review earns 0. The 2027 Information Bulletin states that negative marking applies in Section A and in Section B alike, so a wrong integer answer is penalised just as a wrong option is. Some coaching pages still circulate older material that describes a choose-any-5-of-10 numerical section and no penalty for it; for 2027 the bulletin lists exactly five numerical questions per subject with no choice stated, so ignore any advice that depends on skipping five of ten. Where the bulletin and a third-party page disagree, the bulletin governs.

In Section B you enter an integer with the mouse on an on-screen virtual numeric keypad; the key is the answer rounded to the nearest integer, and candidates are told to calculate with the constants given in the question itself. This rule has a direct consequence for this book: whenever a question says g = 10 m/s² or takes a value such as the speed of light as 3 × 10⁸ m/s, that statement overrides the more exact value in the constants table below, in either section. The question paper appears in English and in the language chosen by the candidate, out of thirteen languages (English, Hindi, Assamese, Bengali, Gujarati, Kannada, Malayalam, Marathi, Odia, Punjabi, Tamil, Telugu and Urdu); if the versions differ, the English version prevails.

Two sessions are planned for 2027, in January and April, and the same syllabus applies to both. For Session 1 the Public Notice dated 24 October 2026 fixes online application from 24 October to 22 November 2026 (up to 11:50 pm), late submission with a late fee of Rs 500 from 23 to 26 November, a correction window from 27 to 29 November, city intimation on 30 December 2026, admit cards on 13 January 2027, and examination dates of 20, 21, 22, 23, 24 and 28 January 2027. Shifts run from 9:00 am to 12:00 noon and from 3:00 pm to 6:00 pm IST. Dates can be revised, so confirm them on the NTA portal before acting on them.

The Physics Syllabus Map: Twenty Units and Where Each Is Taught

The NTA syllabus for JEE (Main) 2027 lists twenty Physics units, the last of which, Experimental Skills, is a practical unit rather than a body of theory. The older lists that many coaching pages still follow carry two items that are absent now: Communication Systems and Physics, Technology and Society. The 2027 unit text does not name the Doppler effect or the radioactive decay law (Unit 10 stops at beats, and Unit 18 at fission and fusion), so this book gives them only a passing mention; if a later notice restores them, learn them from NCERT. Capacitors and dielectrics, on the other hand, sit inside the Electrostatics unit and are examinable. Always judge a topic by the NTA text of the unit, not by whether a coaching module happens to include it.

This book has ten chapters rather than twenty, because neighbouring units share formulae and are easier to revise together. The table below fixes the home of every unit. Experimental Skills is not collected in one place; each experiment is taught beside the physics that underlies it, so the metre-bridge method appears with current electricity and the resonance tube with waves. Vernier callipers and the screw gauge, experiments 1 and 2 of Unit 20, are taught at the end of this chapter, since they are exercises in least count and error, which is exactly the content of Unit 1. When a later chapter needs a constant or an error rule, it points back here instead of repeating it.

Strategy for a Formula-Driven Physics Section

Start from the arithmetic of the marking scheme. With +4 for a right answer and -1 for a wrong one, a blind guess among four options has an expected score of (1/4)(4) + (3/4)(-1) = +0.25 marks. That tiny positive figure is misleading, because it assumes the guess is truly random and ignores the variance. The real lever is elimination. Remove one option on solid grounds and the chance of success becomes 1/3, giving an expected +0.67; remove two and it becomes 1/2, giving +1.5. Break-even occurs at a success probability p with 4p - (1 - p) = 0, so p = 0.2: attempt a question whenever you honestly believe your chance exceeds one in five.

Section B follows different logic. There are no options to eliminate, and the answer is an integer, so an unfounded guess has a chance close to zero of being right and an expected value close to -1. Treat numerical questions as problems to be solved or skipped, not guessed. A useful habit is to estimate the magnitude of the answer first, using orders of magnitude; if the estimate says the answer lies between 40 and 60, a calculation that yields 4.7 × 10⁵ is wrong before you even look at options. Because the answer is rounded to the nearest integer, keep two or three significant figures during the working and round only at the end.

Time is the second budget. Physics has 25 questions in roughly one hour of a three-hour paper, which is about 2.4 minutes each on average; a sensible plan is to spend 1 to 1.5 minutes on direct formula questions and bank the saved minutes for multi-step numerical problems. Take the paper in passes: first answer every question whose formula and route you see at once, then return to the longer ones. Because calculators are not allowed, train mental arithmetic: know squares to 25, √2 = 1.414, √3 = 1.732, π ≈ 3.14, π² ≈ 9.87, and convert awkward numbers into powers of ten early so that only mantissas need multiplying.

Use this book as a loop and not as a reading assignment. For each result, read the formula, the condition under which it is valid, and the pitfall; then close the page and try to restate all three. Worked examples are there to show the route and the units, so attempt the question before reading the steps. Unlike a textbook, the formulas lists and tables here are compact on purpose, which means they assume you have met the idea in your class notes or NCERT. Mark first the formulas whose conditions you cannot state (v = u + at, E = V/d, Bernoulli's equation) and test those, because the +4/-1 paper punishes condition errors more than recall errors.

SI Units, Fundamental and Derived Quantities, and Physical Constants

A physical quantity is stated as a number times a unit, and a system of units is a set of agreed fundamental units from which every other (derived) unit is built. The SI system has seven base quantities. Since the 2019 redefinition, the SI is defined by fixing exact numerical values of seven constants, including the Planck constant h, the elementary charge e, the Boltzmann constant k_B, the Avogadro constant N_A and the speed of light c. Older systems still appear in problems: CGS uses centimetre, gram and second, and FPS uses foot, pound and second. Conversion questions in JEE are routine but unforgiving, so you must be fluent in the powers of ten that link them, such as 1 J = 10⁷ erg and 1 N = 10⁵ dyne.

Derived units get their own names when they are used often. The newton (kg m/s²) measures force, the joule (N m) energy and work, the watt (J/s) power, the pascal (N/m²) pressure, the hertz (1/s) frequency, the coulomb (A s) charge, the volt (J/C) potential, the ohm (V/A) resistance, the farad (C/V) capacitance, the tesla (N/(A m)) magnetic field, the weber (T m²) magnetic flux and the henry (V s/A) inductance. Plane angle (radian) and solid angle (steradian) are dimensionless: they are ratios of lengths. Two traps recur. Mass in SI is the kilogram, not the gram, so any formula with mass must have grams converted before computing. And a unit symbol for a person's name is capitalised (N, J, Pa) but the unit spelled in full is not (newton, joule).

Constants are handled in two ways in the paper: some questions give the value needed, while others expect a standard value from memory. The table below lists the 2022 CODATA values from NIST, whose exact ones follow directly from the SI definitions, beside the rounded values that are convenient in a calculator-free examination. For Section B the bulletin (para 2.4.2) advises using the constants given in the question; the same is sensible practice in Section A, where the stem always fixes the values to use. Note also that after the 2019 redefinition the vacuum permeability μ₀ is no longer exactly 4π × 10⁻⁷ N/A²; its measured value is 1.25663706127 × 10⁻⁶ N/A², which differs from 4π × 10⁻⁷ only in the eleventh significant figure (a relative difference of about 1 part in 10¹⁰), so you can safely keep using 4π × 10⁻⁷.

Master Table of Physical Constants (CODATA 2022)

The constants below are used throughout the book and are not tabulated again in later chapters. The first column gives the quantity; the second gives the CODATA 2022 value with the units; the third gives the rounded form that is customarily supplied or sufficient for a three-significant-figure answer. Exact constants (h, e, k_B, N_A, c) have no uncertainty by definition. Constants such as G are known to only about five significant figures, which is why a JEE paper that needs G always states it.