Education

  Refraction of Light Refraction of Light :  Happens in Transparent medium when a light travels from one medium to another, refraction takes place. A ray of light bends as it moves from one medium to another Refraction is due to change in the speed of light as it enters from one transparent medium to another. Speed of light decreases  as the beam of light travel from rarer medium to the denser medium. Some Commonly observed phenomenon due to Refraction Your eyes. Rainbows. Light bending in a glass of water. Glasses. Camera lenses. Object dislocation in water. Binoculars.. Refraction through a Rectangular Glass Slab When a incident ray of light AO passes from a rarer medium (air) to adenser medium (glass) at point. O on interface KL, it will bends towards the normal. At ptO1, on interface NM the light ray entered from denser medium(glass) to rarer medium (air) here the light ray will bend away from normal OO1 is a refracted ray OB is an emergent ray. If the incident r...

  LIGHT REFLECTION  Light is a form of energy, which gives us the power of vision. In this chapter we will study the phenomena of reflection and refraction using the property of light i.e. straight line propagation (Light wave travel from one point to another, along a straight line). Ray of light : It is a line in the direction of movement of light. Beam of light : It is bucnh of rays of light. Parallel beam : All the rays are parallel. Reflection of Light When the light is allowed to fall on highly polished surface, such as mirror, most of the light gets reflected. Laws of Reflection 1. The angle of incidence is always equal to angle of reflection. 2. The incident ray, reflected ray and the normal to the reflecting surface at the point of incidence lie in the same plane. Image formed by Plane Mirror  (Plane reflecting surface) 1. Virtual (imaginary) & Erect : The image that do not form on screen. Real images can be recorded on the screen. 2. Laterally inverted (...

  HUMAN EYE : It acts like a camera, enable us to capture the colourful picture of the surroundings. An inverted, real image on light sensitive  is formed on the  Retina The Various Parts of Eye and their Functions 1. Cornea  : It is a thin membrane through which light enters. It forms the transparent bulge on the front of eyeball. Most of the refraction occurs at the outer surface of the cornea. 2.  Eyeball  :it is a convex lens, approximately spherical in shape, with a diameter of about 2.3 cm. It can alter its curvature with help of ciliary muscles. 3.  Iris : It is a dark muscular diaphragm that controls the size of pupil.It is behind the cornea.it helps in accommodation of light by changing the size of the pupil. 4.  Pupil  :It regulates and control the amount of light entering the eye. It is the black opening between aqueous humour& lens.BLack in colour. Light entering cannot exit. 5.  Crystalline eye lens  :Prov...