After The School
Class 10PhysicsChapter 10: Light — Reflection and Refraction

Key Formulas

Summary of key formulas for Light — Reflection and Refraction.

Key Formulas

ConceptFormula
Mirror formula1v+1u=1f\dfrac{1}{v} + \dfrac{1}{u} = \dfrac{1}{f}
Lens formula1v−1u=1f\dfrac{1}{v} - \dfrac{1}{u} = \dfrac{1}{f}
Magnification (mirror)m=−vum = -\dfrac{v}{u}
Snell's Lawn1sin⁡θ1=n2sin⁡θ2n_1 \sin\theta_1 = n_2 \sin\theta_2
Refractive indexn=cvn = \dfrac{c}{v}
Power of lensP=1fP = \dfrac{1}{f} (in metres)

10.4 Refraction by Spherical Lenses

Lens formula, power of a lens, and worked example for spherical lenses.

12.1 Electric Current

Definition of electric current and the ampere as a unit of measurement.

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Key Formulas