Study Materials

NCERT Solutions for Class 8th Science

 

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Chapter 16. Light

Chapter Review

 

 

 

Chapter Review:

  • Light is reflected from all surfaces.
  • The light ray, which strikes any surface, is called the incident ray.
  • The ray that comes back from the surface after reflection is known as the reflected ray.  
  • Reflection from a smooth surface like that of a mirror is called regular reflection. 
  • When all parallel rays reflected from a plane surface are not parallel, the reflection is known as  diffused or irregular reflection. 
  • The angle between the normal and incident ray is called the angle of incidence (∠i).
  • The angle between the normal and the reflected ray is known as the angle of reflection (∠r).
  • The incident ray, the normal at the point of incidence and the reflected ray all lie in the same plane.
  • The angle of incidence is always equal to the angle of reflection. This is known as the law of reflection.
  • An image formed by a mirror the left of the object
    appears on the right and the right appears on the left. This is known as lateral inversion.
  • The objects which shine in the light of other objects are called illuminated objects.
  • The objects which emit their own light are known as luminous objects.
  • Splitting of light into its colours is known as dispersion of light.
  • Outer coat of the eye is white. Its transparent front part is called cornea.
  • Behind the cornea a dark muscular structure called iris.
  • The size of the pupil is controlled by the iris.
  • The lens focuses light on the back of the eye, on a layer called retina.
  • At the junction of the optic nerve and the retina, there are no sensory cells, so no vision is possible at that spot. This is called the blind spot.
  • A normal eye can see nearby and distant objects clearly.
  • The most popular resource for visually challenged persons is known as Braille.
  • Sunlight, called white light but consists of seven
    colours.

 

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