Exam 33: Lenses and Optical Instruments

The Moon has a diameter of 3.48 * 10³ km,and is at a distance of 3.84 * 10⁵ km from the Earth's surface.A camera with a lens of focal length 400 mm is used to photograph the Moon.What is the diameter of the Moon's image on the film?

An eye has a near-point at 125 cm.What focal length contact lens will be needed to move the near-point to 25 cm?

You need a converging lens of focal length 14 cm for your science project but you have a converging lens of focal length 10 cm.However,you do have a large variety of diverging lenses.What focal length diverging lens would you combine in contact with the converging lens to obtain the lens you need? (Assume the distance between the lenses is very small.)

A camera has a lens with a focal length of 60 mm.Suppose you replace the normal lens with a zoom lens whose focal length can be varied from 35 mm to 250 mm.and use the camera to photograph an object at infinity.Compared to a 60 mm lens,what magnification of the image would be achieved using the 240 mm focal length?

An object 1.0 cm high is projected onto a screen using a converging lens with a focal length of 35 cm.The image on the screen is 28 cm high.What is the distance of the object from the lens?

As objects are moved closer to the human eye,the ciliary muscle causes the lens at the front of the eye to become more curved,thereby decreasing the focal length of the lens.The shortest focal length of this lens is typically 2.3 cm.What is the closest one can bring an object to a normal human eye and still have the image of the object projected sharply on the retina,which is 2.5 cm behind the lens?

Two lenses are used to create an image of a 15.0-cm tall source that is located 43.0 cm to the left of the first lens,which is a biconcave thin polycarbonate lens (index of refraction n = 1.67)and has a radius of curvature of 25.0 cm for both front and back surfaces.The second lens is 36.0 cm to the right of the first lens.The second lens is a converging lens with a focal length magnitude of 25.0 cm.What is the magnification?

An object is 50-cm from a screen.What would be the focal length of a converging lens that will form an image on the screen twice the height of the object?

Which kind of lens never suffers from chromatic aberration?

A double lens system is made of +35.0 cm lens (lens #1)and a -26.0 cm lens (lens #2).Lens #1 is placed at x = 0 cm on a meter stick and lens #2 is placed at x = 30.0 cm.Where on the meter stick will the final image be formed when looking at a distant object?

Using ray tracing,find the image of the object (upright arrow)in the system shown having a diverging lens where f is a focal point.Which one of the statements is true?

Each sketch shows a converging lens of focal length f,an object,and an image.The object is black and the image is grey.Which of the drawings could be correct?

A convex lens with index of refraction n = 1.60 has two spherical surfaces as shown in the diagram.The radius of curvature of the left face is r1 = 1.50 m.The radius of curvature of the right face is r2 = 1.70 m.What is the power (in diopter)of this lens?

An object is 120 cm to the left of a thin bi-convex lens with index of refraction of 1.50 and radii of curvature of 30 cm and 60 cm.Where will the image form?

An object is placed 50 cm in front of a diverging lens.What are the correct signs for the image distance,image height,and focal length for lens?

What is the focal length of a magnifying glass that gives a magnification of 5?

Starting with a real object,which of the following statements about the image formed by a single lens is incorrect?

How large does a 5 mm insect appear when viewed with a system of two identical lenses of focal length 5 cm separated by a distance 12 cm if the insect is 10 cm from the first lens?

If I cannot focus on anything closer than 40 cm from my eyes,what type of correction lens would I need to buy to be able to read at the normal near point of 25 cm?

A refracting telescope has the objective lens of focal length 15.0 m.Assume it is used with an eyepiece of focal length 5.00 cm.What is the magnification of this telescope?