Uses of Convex Lens and Concave Lens.jpg

We saw that, image formed by convex lens is

Position of the object Position of the image Relative size of the image  Nature of the image
At infinity  At focus F 2   Highly diminished,  point-sized Real and inverted
Beyond 2F 1   Between F 2 and 2F Diminished  Real and inverted
At 2F 1   At 2F 2   Same Size Real and inverted
Between F 1 and 2F Beyond 2F 2   Enlarged  Real and inverted
At focus F At infinity Infinitely large or
highly enlarged
Real and inverted
Between focus F 1 and optical Center O On the same side of the lens as the object Enlarged  Virtual  and erect


Now, let us see where convex lens is used

 

Convex lens is used as

  • It is used as Magnifying Glass
  • It is used to Make Microscope
  • It is used in spectacles to correct the vision. It cures defects called hypermetropia (far sightedness) where patients can't see objects closer to them

 

Uses of Concave Lens

We saw that, image formed by concave lens is

Position of the object Position of the image Relative size of the image  Nature of the image
At infinity  At focus F 1 Highly diminished, Point - Sized  Virtual and erect
Between infinity and optical centre O of the lens  Between focus F 1 and optical centre O  Diminished Virtual and erect


Now, let us see where concave lens is used

 

Concave lens is used as

  • It is used as a spy hole in doors (where we can see visitor from a small opening)
  • It is used in spectacles to correct the vision. It cures defects called myopia (near sightedness) where patients can't see objects far away
  • They are used in camera to focus on a single object, Hence we get a clearer picture
  • It is used in Flashlights. Concave lenses are used in flashlights to widen the beam produced by the bulb.
  1. Class 10
  2. Chapter 10 Class 10 - Light - Reflection and Refraction

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.