Question

A 5 cm tall object stands in front of a converging lens with focal length f = 35 cm. The distance between the object and the lens is 10 cm. (a) Give the power of the lens. (b) Calculate the position and height of the image formed. Is the image real or virtual? (c) In the space below clearly produce the ray diagram (at least two of the three rays that form the image). A farsighted person uses spectacles formed with these lenses to clearly see an object located at 25 cm from his eyes. The lenses are held 2 cm from his eyes. (d) What is the person’s near point?

Answer 1

Class Nore Date object distance 0 2 10 cm Given focal length f= 35cm height of image to = 5cm power of lens pat 20.0285 2/2,85 Diophe. The thin lens equation is 4366 1052 La (b) 350m Tom locm Image distance 2 = -14cm Magnification of imago M- - I . - (-10 m) - 1.4 Height of image ho a Mho (104) (5cm) 27 cm The image is (virtual and upright