1. Which material will produce a converging lens with the longest focal length?
(A) Lucite
(B) Crown glass
(C) Flint glass
(D) Quartz

2. An object is placed in front of a converging lens in such a way that the image produced is inverted and larger. If the lens were replaced by one with a larger index of refraction, the size of the image would
(A) increase
(B) decrease
(C) increase or decrease, depending on the degree of change
(D) remain the same

3. You wish to make an enlarged reproduction of a document using a copying machine. When you push the enlargement button, the lens inside the machine moves to a point
(A) equal to f
(B) equal to 2f
(C) between f and 2f
(D) beyond 2f

4. A negative image distance means that the image formed by a concave mirror will be
(A) real
(B) erect
(C) inverted
(D) smaller

5. Real images are always produced by
(A) plane mirrors
(B) convex mirrors
(C) concave lenses
(D) convex lenses

6. The focal length of a convex mirror with a radius of curvature of 8 cm is
(A) 4 cm
(B) −4 cm
(C) 8 cm
(D) −8 cm

7. An object appears in front of a plane mirror as shown below:

Which of the following diagrams represents the reflected image of this object?

8. An object is located 15 cm in front of a converging lens. An image twice as large as the object appears on the other side of the lens. The image distance must be
(A) 15 cm
(B) 30 cm
(C) 45 cm
(D) 60 cm

9. A 1.6-meter-tall person stands 1.5 m in front of a vertical plane mirror. The height of his image is
(A) 0.8 cm
(B) 2.6 cm
(C) 3.2 cm
(D) 1.6 cm

10. An object is 25 cm in front of a converging lens with a 5-cm focal length. A second converging lens, with a focal length of 3 cm, is placed 10 cm behind the first one.
   (a) Locate the image formed by the first lens.
   (b) Locate the image formed by the second lens if the first image is used as an “object” for the second lens.
   (c) What is the combined magnification of this combination of lenses?

11. Why do passenger-side mirrors on cars have a warning that states: Objects are closer than they appear?

12. Two lenses have identical sizes and shapes. One is made from quartz (N = 1.46), and the other is made from glass (N = 1.5). Which lens would make a better magnifying glass?

13. Why do lenses produce chromatic aberration whereas spherical mirrors do not?