Chapter 1: Units and Measurements
Units and Measurements is the gateway chapter of Class 11 Physics and the first topic every JEE Main and NEET aspirant must master, because every later chapter — from Laws of Motion to Current Electricity — expresses its results as numbers with units, checked by dimensions. This hub gives you the complete, exam-aligned map of the chapter: the International System of Units (SI) with its seven base units and prefixes, the discipline of significant figures and rounding, dimensions of physical quantities, dimensional formulae and dimensional equations, the three applications of dimensional analysis, and the language of accuracy, precision and errors in measurement. NTA tests this chapter mainly through dimension-matching MCQs, significant-figure numericals, unit-conversion integer-answer questions and Assertion–Reason items. Work through the seven topic pages below in NCERT order, attempt the drill questions on each page, then take the 30-question chapter test with full answer key.
Topics in this chapter
- § 1.1 Introduction to Units and MeasurementIntroduction to units and measurement for Class 11 Physics: physical quantities, fundamental vs derived and the NCERT ranges of length, mass and time — JEE…
- § 1.2 International System of Units (SI Units)International System of Units for Class 11 Physics: all 7 SI base units, supplementary units, prefixes and symbol rules — with practice Qs for JEE Main, NEET.
- § 1.3 Significant Figures: Rules & RoundingSignificant figures rules: counting, ×/÷, +/−, round-half-to-even and the log rule — Class 11 notes with solved examples and practice for JEE Main, NEET.
- § 1.4 Dimensions of Physical QuantitiesDimensions of physical quantities for Class 11: base dimensions, derivations of [F], [G], [h], [η], [B], dimensionless quantities, homogeneity — JEE Main…
- § 1.5 Dimensional Formulae and Dimensional EquationsDimensional formulae and dimensional equations for Class 11: 30-quantity master table, family memory hooks and worked derivations — JEE Main, NEET notes.
- § 1.6 Dimensional Analysis and Its ApplicationsDimensional analysis and its applications for Class 11: checking equations, deriving pendulum and wave relations, unit conversions, limits — JEE Main, NEET.
- § 1.7 Errors in Measurement: Accuracy & PrecisionErrors in measurement for Class 11 Physics: accuracy vs precision, absolute, relative and percentage error, combination of errors and least count — JEE, NEET.
- ✓ Chapter testAttempt all questions, then submit to see your score and the explanation for every answer.