A person can see objects lying between 50 cm and 100 cm. What power of lens will he use for reading a book ? (Distance of L.D.V. is 25 cm) :

A person can see objects lying between 50 cm and 100 cm. What power of

1.	A person can see objects lying between 50 cm and 100 cm. What power of lens will he use for reading a book ? (Distance of L.D.V. is 25 cm) :
Answer» <P>`+ 2D` `-2 D` `+ 0.2 D` `- 0.2 D` Solution :(a) Nearest DISTANCE upto which he can see CLEARLY is 50 cm and distance upto which he WISHES to see clearly is 25 cm. `therefore (1)/(F) = (1)/(25) - (1)/(50) or f = 50 cm, P = (100)/(50) = + 2D`.

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A person can see objects lying between 50 cm and 100 cm. What power of lens will he use for reading a book ? (Distance of L.D.V. is 25 cm) :

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