An object is placed 36 cm to the left of a converging lens. The resulting image is five times the size of the object and projected onto a screen. What is the focal length of this lens? a. f = +30 cm. b. f = +45 cm. c. f = +36 cm. d. f = +180 cm. e. f = –45 cm.

An eyeglass prescription that specifies a power of -1.0 diopters is describing a lens that has a focal length of O a. + 1 meter O b.- 100 cm O C. - 1 meter O d. - 1 cm An object placed 25 cm to the left of a +20 cm focal length lens produces a real image 100 cm to the right of the lens. What is the magnification? O a. - 4 Ob. - 0.25 O C. + 2 O d. - 1

An image of the moon is focused onto a screen using a converging lens of focal length f= 35.3 cm. The diameter of the moon is 3.48×106 m, and its mean distance from the earth is 3.85x108 m. What is the diameter of the moon's image? 8.29E-12 m

Two converging lenses create an image 1.50 m away from the obiect. The first lens is placed 30 cm in front of the object. The first lens has a focus length of 20 cm and the second has a focus length of 15 cm. How far apart are the lenses be (x=?)? Drawing not to scale. X=? 30 cm 1.5 m

1. How far from the object should the lens be held?

7. An object is placed 50.0 cm in front of a lens of focal length f = 22.0 cm a. What is the image distance? di = b. If the object height is 5.0 cm, what is the image height?

A contact lens is made of plastic with an index of refraction of 1.60. The lens has an outer radius of curvature of +1.91 cm and an inner radius of curvature of +2.49 cm. What is the focal length of the lens? cm Need Help? Watch It Read It