Ch 16 goes deeper into light — laws of reflection, regular vs diffused reflection, how the human eye works, care of the eyes, and aids for visually impaired people.
Law 1: Angle of incidence = Angle of reflection. Law 2: Incident ray, reflected ray, and normal all lie in the same plane. Regular reflection: smooth surfaces reflect parallel rays in one direction (mirror). Diffused reflection: rough surfaces scatter light in many directions (wall, paper).
Light enters through cornea → pupil (opening controlled by iris) → lens (focuses light) → retina (image formed here). Retina has nerve cells that send signals to brain via optic nerve. Iris adjusts pupil size: dilates in dark, contracts in bright light. Braille system uses raised dots for visually impaired reading.
Download: https://ncert.nic.in/textbook/pdf/hesc116.pdf | Complete book: https://ncert.nic.in/textbook/pdf/hesc1ps.zip
Yes, very much so. Diffused reflection from walls, furniture, and objects is what allows us to see things around us. Without diffused reflection, we would only see light sources directly and everything else would appear completely dark.
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