Exam 23: Mirrors and Lenses

Two thin lenses,with focal lengths of 22.0 cm and -40.0 cm are placed in contact in an orientation so that their optic axes coincide.What is the focal length of the two in combination? {Hint: A thin lens is one whose thickness is negligible).

Parallel rays of light that hit a concave mirror will come together:

A contact lens is made of plastic with an index of refraction 2.70.The lens has an outer radius of curvature of + 3.3 cm and an inner radius of curvature of + 4.5 cm.What is its focal length?

A lens of 10.0-cm focal length is placed 29.0 cm to the right of the object and a mirror of focal length -20.0 cm is placed 49.0 cm to the right of the lens.Where is the image formed by the mirror?

A lens has a focal length of 41 cm in air.If this lens were immersed in water,what focal length would result? The index of refraction of the lens is 2.200 and that of water is 1.333.The focal length of a thin lens with index n₁ submerged in a liquid with index n₂ is given by the modified lens maker's formula: )

A lens of 13.0-cm focal length is placed 29.0 cm to the right of the object and a mirror of focal length -19.0 cm is placed 39.6 cm to the right of the lens.Where is the final image formed?

A glass block,for which n = 1.52,has a blemish located 5.0 cm from one surface.At what distance from that surface does the image of the blemish appear to the outside observer?

A convex mirror with a focal length of -17 cm forms an image 12 cm behind the surface.If the object height is 1.0 cm what is the image height?

A 80-cm focal length thin lens is placed in contact with one of 59.5 cm focal length.A 2.3 cm tall object is placed 55 cm in front of the combination.What is the size of the image?

An object and a screen are separated by 26.0 cm.A convex lens is placed between them,9.00 cm from the object.In this position it causes a sharp image of the object to form on the screen.What is the focal length of the lens?

Which of the following effects is the result of the fact that the index of refraction of glass will vary with wavelength?

An object,located 96 cm from a concave lens,forms an image 34 cm from the lens on the same side as the object.What is the focal length of the lens?

Which of the following best describes the image of a concave mirror when the object is at a distance greater than twice the focal point distance from the mirror?

A goldfish is swimming in water (n = 1.33)inside a spherical plastic bowl of index of refraction 1.33.If the goldfish is 12 cm from the front wall of the 23-cm radius bowl,where does the goldfish appear to an observer in front of the bowl?

In an ideal case rays coming from an object toward a lens or mirror should be reasonably close to the optic axis.To the extent that this condition is not completely met,which one of the following effects occurs?

An object placed 18.0 cm from a concave mirror produces a real image 16.0 cm from the mirror.If the object is now moved to a new position 22.0 cm from the mirror,where is the new image located as measured from the mirror?

For a diverging lens with one flat surface,the radius of curvature for the curved surface is 27.0 cm.What must the index of refraction be so that the focal length is -15.0 cm?

When the reflection of an object is seen in a concave mirror the image will:

An eyeglass lens is cut with one surface having a radius R₁ and the other surface having a radius R₂,with R₁ < R₂.Both positive radii are measured from the same side with R₁ being the side closer to the eye.Is this convex-concave lens a converging lens or a diverging lens?

A container is filled with fluid 1 and the apparent depth of the fluid is 5 cm.The container is next filled with fluid 2,and the apparent depth of this fluid is 3 cm.What is the ratio of the indices of refraction of these fluids?