Kisi Uttar Lens ki focus Doori 25 CM Hai To Uska chamta Kya Hogi
Answers
Answer:
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative focal lengh indicates that the system diverges light. A system with a shorter focal length bends the rays more sharply, bringing them to a focus in a shorter distance or diverging them more quickly. For the special case of a thin lens in air, a positive focal length is the distance over which initially collimated (parallel) rays are brought to a focus, or alternatively a negative focal length indicates how far in front of the lens a point source must be located to form a collimated beam. For more general optical systems, the focal length has no intuitive meaning; it is simply the inverse of the system's optical power.
Answer:
focus lenght of lens=25cm=25/100=0.25m
efficiency of lens=1/focus lenght(m)
=1/0.25m
=100/25
=4D
=4 Diopter. ans