The human eye can focus objects at different distances by adjusting the focal length of the eye lens.

(a) are relaxed and lens becomes thinner

(b) Human eye can change the focal length of the eye lens to see the objects situated at various distances from the eye. This is possible due to the power...

The power of a lens is related to its focal length as P = \(\frac{1}{f}\)(in m) More the power of a lens more is its converging power. Thus, the lens of shorter focal...

Given P=+ 1.5D As P=1/f (in metre) , Focal length, f =1/P=1/1.5=0.667m=66.7cm As power of prescribed lens is positive, the lens is converging (or convex) lens.

P=1/f , P∝1/f. Power of a lens is inversely proportional to its focal length therefore lens having focal length of 20 cm will provide more convergence.

(d) the eye is not able to decrease the focal length beyond a limit.

(d) The image-distance from the eye-lens.

The correct answer is (a) =x

(b) L > u (d) L > 2fo.

1/f = 1/v - 1/u = 1/v = 1/f + 1/u Here, u = - f and for a concave lens f = -f Therefore, 1/v = - 1/f - 1/f  =>...