CLASS 11 PHYSICS • NCERT NOTES
Chapter 1: Units and Measurements
Comprehensive Revision Sheet • Master Definitions, Formulas & Shortcuts
1. Fundamental & Supplementary Quantities
Physical quantities that do not depend on any other physical quantity for their measurement are called Fundamental
Quantities.
Base Quantity SI Unit Symbol Dimension
Length Meter m [L]
Mass Kilogram kg [M]
Time Second s [T]
Electric Current Ampere A [I] or [A]
Thermodynamic Temp. Kelvin K [K] or [θ]
Amount of Substance Mole mol [mol]
Luminous Intensity Candela cd [cd]
Plane Angle ( dθ) Solid Angle ( dΩ)
Unit: Radian (rad) Unit: Steradian (sr)
Formula: dθ = ds / r Formula: dΩ = dA / r²
Ratio of arc length to radius. Dimensionless. Ratio of intercepted area to squared radius.
2. Systems of Units
CGS System FPS System MKS System
Centimeter, Gram, Second. Used in Foot, Pound, Second. British Meter, Kilogram, Second. Basis for
laboratory-scale physics. engineering system. modern SI units.
3. Important Dimensional Formulas
Physical Quantity Formula Dimensional Formula
Velocity / Speed Distance / Time [M⁰ L T⁻¹]
Acceleration Velocity / Time [M⁰ L T⁻²]
Force Mass × Acceleration [M L T⁻²]
Work / Energy Force × Displacement [M L² T⁻²]
Pressure / Stress Force / Area [M L⁻¹ T⁻²]
Power Work / Time [M L² T⁻³]
Class 11 Physics • Chapter 1 Notes Page 1 of 2
Chapter 1: Units and Measurements
Comprehensive Revision Sheet • Master Definitions, Formulas & Shortcuts
1. Fundamental & Supplementary Quantities
Physical quantities that do not depend on any other physical quantity for their measurement are called Fundamental
Quantities.
Base Quantity SI Unit Symbol Dimension
Length Meter m [L]
Mass Kilogram kg [M]
Time Second s [T]
Electric Current Ampere A [I] or [A]
Thermodynamic Temp. Kelvin K [K] or [θ]
Amount of Substance Mole mol [mol]
Luminous Intensity Candela cd [cd]
Plane Angle ( dθ) Solid Angle ( dΩ)
Unit: Radian (rad) Unit: Steradian (sr)
Formula: dθ = ds / r Formula: dΩ = dA / r²
Ratio of arc length to radius. Dimensionless. Ratio of intercepted area to squared radius.
2. Systems of Units
CGS System FPS System MKS System
Centimeter, Gram, Second. Used in Foot, Pound, Second. British Meter, Kilogram, Second. Basis for
laboratory-scale physics. engineering system. modern SI units.
3. Important Dimensional Formulas
Physical Quantity Formula Dimensional Formula
Velocity / Speed Distance / Time [M⁰ L T⁻¹]
Acceleration Velocity / Time [M⁰ L T⁻²]
Force Mass × Acceleration [M L T⁻²]
Work / Energy Force × Displacement [M L² T⁻²]
Pressure / Stress Force / Area [M L⁻¹ T⁻²]
Power Work / Time [M L² T⁻³]
Class 11 Physics • Chapter 1 Notes Page 1 of 2
