Lenses of focal lengths +60 mm & +20.8 mm are held 93.9 mm apart to make a makeshift microscope.  A leaf of length 1.76 cm is placed 200 mm from the larger focal length lens.  How large will the virtual image appear when viewed through the other lens?  Answer in cm, and use + for upright and - for inverted.

You are using a microscope with a 10× eyepiece. What focal length of the objective lens will give a total magnification of 200×? Assume a length L = 160 mm.

A farsighted person has a near-point of 92 cm. To correct their vision so that they can see objects that are as close as 10 cm to their eye, what should be the focal length of the prescribed lens? Assume the lens will be 2 cm from the eye. Enter a number with units.

A symmetric double convex lens with a focal length of 26.0 cmcm is to be made from glass with an index of refraction of 1.52. What should be the radius of curvature for each surface? Express your answer to two significant figures and include the appropriate units.

A slide projector needs to create a 88-cmcm-high image of a 2.0-cmcm-tall slide. The screen is 340 cmcm from the slide. What focal length does the lens need? Assume that it is a thin lens. Express your answer with the appropriate units. Enter positive value if the lens is converging and negative value if the lens is diverging.   How far should you place the lens from the slide? Express your answer with the appropriate units.

An individual is nearsighted; his near point is 11.0 cm and his far point is 51.0 cm. (a) What lens power is needed to correct his nearsightedness? 1.96 X The response you submitted has the wrong sign. diopters (b) When the lenses are in use, what is this person's near point? 11 X Your response differs from the correct answer by more than 10%. Double check your calculations. cm

An upright object is placed a distance in front of a converging lens equal to twicethe focal length of the lens. On the other side of the lens is a converging mirror of focallength , separated from the lens by a distance ; see diagram below. Find the location, nature, and relative size of the final image, as seen by an eye looking toward the mirrorthrough the lens. Draw the appropriate ray diagram

In a two-lens system, the focl length of the lens is f1 = 4.00 cm, and that of then lens 2 is f2 = 8.00 cm. The distance between the lenses is 16 cm. If an object O is 2.00 cm high and is placed 6.00 cm in front of the lens 1, where is the final image through the two-lens system?

A lens has a focal length of 48 cm and a diameter of 10.00 cm. What is the f-number of the lens?