An object is placed at a distance of 20cm in front of a convex lens of focal length 18cm . Find the position of image

Answer 1

Given u= (-20cm)
f = (+18cm)
V =?
Lens formula: (1/f) = (1/v) - (1/u)
Thus, (1/v) = (1/f) + (1/u)
= (1/18) -  (1/20)
= (20/360) - (18/360)
= (20 - 18)/360
= 2/360
= 1/180
Therefore, v = 180 cm = 1.8 m