Units & Measurements
Class 11 · Units & Measurements
Derivation by Dimensions
Walk through 4 classic derivations — pendulum period, Bohr radius, projectile range, gravitational force.
Key Notes
01
Assume quantity Q depends on parameters xᵢ through powers: Q = k·x₁ᵃ·x₂ᵇ·…
02
Match dimensions on both sides to solve for a, b, … .
03
Final answer has an undetermined dimensionless constant k (often 1, 2π, etc.)
Important Points
Works only if the quantity genuinely depends on those parameters via a power law.
Derivation by Dimensions notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 11 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.