Optics

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Light has dual nature - it behaves both as electromagnetic waves and as particles (photons). In vacuum, light travels at c = 3 × 10⁸ m/s, which is the maximum possible speed according to Einstein's sp…

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1. Light travels in straight line in homogeneous and isotropic medium 2. Two or more rays can intersect without affecting their paths beyond intersection 3. Laws of reflection: (a) Reflected ray lies …

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Cartesian sign convention provides consistent rules for optical calculations: • All distances measured from optical center/pole • Incident rays travel left to right • Distances left of pole are negati…

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For spherical mirrors: f = R/2 Where f is focal length and R is radius of curvature. For concave mirror: f is negative (according to sign convention) For convex mirror: f is positive This relationship…

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Given: f = -15 cm, u = -30 cm Using 1/f = 1/v + 1/u 1/(-15) = 1/v + 1/(-30) -1/15 = 1/v - 1/30 1/v = -1/15 + 1/30 = -2/30 + 1/30 = -1/30 v = -30 cm Magnification m = v/u = (-30)/(-30) = 1 Image is rea…

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Spherical aberration occurs when rays far from principal axis don't focus at the same point as paraxial rays, causing fuzzy images. Distance between Fm and Fp is longitudinal spherical aberration. Eli…

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Absolute refractive index: n = c/v (ratio of speed of light in vacuum to speed in medium) Relative refractive index: ₁n₂ = v₁/v₂ = n₂/n₁ (refractive index of medium 2 with respect to medium 1) For any…

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For refraction at plane surface: n = Real depth/Apparent depth This applies when viewing from rarer to denser medium (like looking at bottom of water body from air). Bottom appears raised due to refra…