(b) Why are the traffic light signals (or danger signals) of red color?
Compute the power of this lens.What type of spectacles should be worn by a person having the defects of myopia as well as hypermetropia?Ans i) Ciliary muscles: These are the muscles, which hold the eye lens.(ii) Accommodation: The ability of the eye lens to change its focal length is called accommodation.Class 10 Science Notes Chapter 11 Human Eye and Colourful World.Ans: - When the sun is overhead at noon, then the light coming from the sun has html and css for dummies pdf to travel a relatively shorter distance through the atmosphere to reach.The power of lens is given by power of a lens in dioptre 1/focal length of the lens in meter 1/0.5 -2 dioptre.
The band of seven colours is called spectrum.
Myopia (Short sightedness) : It is a kind of defect in human eye due to which a person can see near objects clearly but he can not see the distant objects clearly.
Its curvature can be adjusted with the help of ciliary muscles.(b) myopia : Myopia is corrected by using spectacles containing concave lenses of suitable focal length.For viewing distant objects, focal length of corrective lens, F -x -1.2 m, p 1 / f 1 / -1.2 -0.83D.The various colours seen are Violet, Indigo, Blue, Green, Yellow, Orange and Red.(ii) Cornea : It is a thin membrane which covers the eye ball.What is the nature and power of the lens required to correct the problem?
Myopia is due to (i) excessive curvature of cornea.