Units and Measurements: notes and previous year questions

Free notes for every topic in units and measurements, with the key formulas and real JEE and NEET questions solved step by step.

SI UnitsWhy we need standard units, the seven base units, derived units, prefixes and conversions.
Dimensional FormulasWhat dimensions are, how to find them, which quantities share them, and the principle of homogeneity.
Dimensional AnalysisUsing dimensions to check equations, derive formulas, find unknown constants and convert units, and where the method stops working.
Errors in MeasurementAccuracy and precision, the three kinds of error, how big an error is, how errors combine in calculations, and least count.
Significant FiguresWhich digits of a measurement can be trusted, how to count them, how to round, and how many to keep in a calculation.