Question

please say correct important​

Answer 1

Explanation:

i) The distance of near point:

If the distance of near point is’d’ and focal length is 'f then the relation between

them f = 25d/d-25 (f in cm)

Given focal length (f) = 150 cm

f = 25d/d-25

150 = 25d/d-25

d-25 = 25d/150

d-25 = d/6

6(d-25) = d

6d-150 = d

6d-d = 150

5d = 150

d = 30cm

ii) Power of lens :

Given that;

f = 150 cm = 1.5m

Power (in diopters) = 1/ f in metres

= 1/150 cm = 1/1.5m = 2/3D