Calculate the focal length of a reading glass of a person if his distance of distinct vision is ( 75 ) ( cm ).

Step-by-step solution

Given, ( v=-75 ~cm ; u=-25 ~cm ). Using ( 1 f - 1 v - 1 u ), we get ( 1 f = 1 -75 - 1 -25 = -1+3 75 = 2 75 ) Therefore ( f= 75 2 =37.5 ~cm ) Thus, focal length of reading glass is ( 37.5 ~cm ).