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प्रश्न
What is meant by optical illusion? Give one example.
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उत्तर
An optical illusion is the life-like continuous movement on the screen. Television is an example of optical illusion, where the scanning beam of a picture frame of the TV camera moves so rapidly on the viewing screen of the TV set that our eyes cannot keep pace with it.
संबंधित प्रश्न
The kind of lens required to correct Myopia
Name the defect of vision in a person:
whose far point is less than infinity
Differentiate between myopia and hypermetropia. What type of spectacles should be worn by a person having the defects of myopia as well as hypermetropia? How does it help?
State one role of ciliary muscles in the human eye.
List two causes of presbyopia. Draw labelled diagram of a lens used for the correction of this defect of vision.
The near point of the eye of a person is 50 cm. Find the nature and power of the corrective lens required by the person to enable him to see clearly the objects placed at 25 cm from the eye?
Draw a neat labeled diagram to show how hypermetropia can be rectified.
Myopia and hypermetropia can be corrected by:
Draw ray diagram showing myopic eye.
Complete the following table by observing the given figures:
| Figure → |  |
 |
| Points ↓ | ||
| (a) Name of the defect | ______ | ______ |
| (b) Position of the image | ______ | ______ |
| (c) Lens used to correct the defect | ______ | ______ |
