CLASS 11 PHYSICS
CHAPTER 1
UNITS AND MEASUREMENTS
Complete Detailed Notes
Formula Sheet • Concepts • Derivations • Solved Examples • Practice Questions • Answer
Key
NCERT/CBSE-oriented • School Exams + Competitive Foundation
Class 11 Physics — Units and Measurements | Page 1
, Chapter Overview & Learning Goals
This chapter develops the language used throughout physics: measurement, units, dimensions, significant figures and
errors. A strong command of this chapter makes later numerical chapters much easier because every physical
equation must use meaningful units and consistent dimensions.
By the end of the chapter, you should be able to:
• Identify SI base and derived quantities.
• Convert units using powers of ten.
• Write dimensional formulae of important physical quantities.
• Check equations using the principle of homogeneity.
• Use significant-figure and rounding rules correctly.
• Calculate absolute, relative and percentage errors.
• Propagate errors through sums, products, quotients and powers.
• Understand least count, Vernier calipers and screw gauge.
• Use dimensional analysis to derive proportional relationships and identify its limitations.
Exam Tip
Do not treat Units and Measurements as a memorisation-only chapter. Most questions become easy when you write the
relevant definition, formula, units and dimensions systematically.
Class 11 Physics — Units and Measurements | Page 2
CHAPTER 1
UNITS AND MEASUREMENTS
Complete Detailed Notes
Formula Sheet • Concepts • Derivations • Solved Examples • Practice Questions • Answer
Key
NCERT/CBSE-oriented • School Exams + Competitive Foundation
Class 11 Physics — Units and Measurements | Page 1
, Chapter Overview & Learning Goals
This chapter develops the language used throughout physics: measurement, units, dimensions, significant figures and
errors. A strong command of this chapter makes later numerical chapters much easier because every physical
equation must use meaningful units and consistent dimensions.
By the end of the chapter, you should be able to:
• Identify SI base and derived quantities.
• Convert units using powers of ten.
• Write dimensional formulae of important physical quantities.
• Check equations using the principle of homogeneity.
• Use significant-figure and rounding rules correctly.
• Calculate absolute, relative and percentage errors.
• Propagate errors through sums, products, quotients and powers.
• Understand least count, Vernier calipers and screw gauge.
• Use dimensional analysis to derive proportional relationships and identify its limitations.
Exam Tip
Do not treat Units and Measurements as a memorisation-only chapter. Most questions become easy when you write the
relevant definition, formula, units and dimensions systematically.
Class 11 Physics — Units and Measurements | Page 2
