1. Q34.1
Which of the following changes its focal length when it is immersed in water?
A. a concave mirror
B. a convex mirror
C. a diverging lens
D. all of the above
E. none of the above
Answer: C

2. A34.1
Which of the following changes its focal length when it is immersed in water?
A. a concave mirror
B. a convex mirror
C. a diverging lens
D. all of the above
E. none of the above

3. Q34.2
A concave mirror with a radius of curvature of 20 cm has a focal length of
A. 40 cm.
B. 20 cm.
C. 10 cm.
D. 5 cm.
E. answer depends on the index of refraction of the air around the mirror
Answer: C

4. A34.2
A concave mirror with a radius of curvature of 20 cm has a focal length of
A. 40 cm.
B. 20 cm.
C. 10 cm.
D. 5 cm.
E. answer depends on the index of refraction of the air around the mirror

5. A. real and larger than the object.
Q34.3
An object is placed 4.0 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.
Answer: B

6. A34.3
An object is placed 4.0 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.

7. A. real and larger than the object.
Q34.4
An object is placed 2.0 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.
Answer: C

8. A34.4
An object is placed 2.0 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.

9. A. real and larger than the object.
Q34.5
An object is placed 1.5 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.
Answer: A

10. A34.5
An object is placed 1.5 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.

11. A. real and larger than the object.
Q34.6
An object is placed 0.5 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.
Answer: D

12. A34.6
An object is placed 0.5 m away from a concave mirror of focal length +1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.

13. A. real and larger than the object.
Q34.7
An object is placed 2.0 m away from a convex mirror of focal length –1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.
Answer: E

14. A34.7
An object is placed 2.0 m away from a convex mirror of focal length –1.0 m. The image formed by the mirror is
A. real and larger than the object.
B. real and smaller than the object.
C. real and the same size as the object.
D. virtual and larger than the object.
E. virtual and smaller than the object.

15. A. only the object’s upper half will be visible in the image.
Q34.8
An object PQ is placed in front of a converging lens, forming a real image P´Q´. If you use black paint to cover the lower half of the lens,
A. only the object’s upper half will be visible in the image.
B. only the object’s lower half will be visible in the image.
C. only the object’s left-hand half will be visible in the image.
D. only the object’s right-hand half will be visible in the image.
E. the entire object will be visible in the image.
Answer: E

16. A34.8
An object PQ is placed in front of a converging lens, forming a real image P´Q´. If you use black paint to cover the lower half of the lens,
A. only the object’s upper half will be visible in the image.
B. only the object’s lower half will be visible in the image.
C. only the object’s left-hand half will be visible in the image.
D. only the object’s right-hand half will be visible in the image.
E. the entire object will be visible in the image.

17. A thin lens has focal length f = –12 cm.
Q34.9
A thin lens has focal length f = –12 cm.
If an object 9 cm tall is placed 24 cm from the lens, what is the height of the image?
A. 27 cm tall
B. 18 cm tall
C. 9 cm tall
D. 4.5 cm tall
E. 3 cm tall
Answer: E

18. A34.9
A thin lens has focal length f = –12 cm.
If an object 9 cm tall is placed 24 cm from the lens, what is the height of the image?
A. 27 cm tall
B. 18 cm tall
C. 9 cm tall
D. 4.5 cm tall
E. 3 cm tall

19. Which statement is true about a farsighted (hyperopic) eye?
Q34.10
Which statement is true about a farsighted (hyperopic) eye?
A. The image point is in front of the retina; a converging eyeglass lens is used to correct this condition.
B. The image point is in front of the retina; a diverging eyeglass lens is used to correct this condition.
C. The image point is behind the retina; a converging eyeglass lens is used to correct this condition.
D. The image point is behind the retina; a diverging eyeglass lens is used to correct this condition.
Answer: C

20. A34.10
Which statement is true about a farsighted (hyperopic) eye?
A. The image point is in front of the retina; a converging eyeglass lens is used to correct this condition.
B. The image point is in front of the retina; a diverging eyeglass lens is used to correct this condition.
C. The image point is behind the retina; a converging eyeglass lens is used to correct this condition.
D. The image point is behind the retina; a diverging eyeglass lens is used to correct this condition.

21. Q34.11
You are choosing lenses for a telescope that you will use to look at the Moon and planets. You should select
A. an objective lens with a long focal length and an eyepiece lens with an even longer focal length.
B. an objective lens with a long focal length and an eyepiece lens with a shorter focal length.
C. an objective lens with a short focal length and an eyepiece lens with a longer focal length.
D. an objective lens with a short focal length and an eyepiece lens with an even shorter focal length.
Answer: B

22. A34.11
You are choosing lenses for a telescope that you will use to look at the Moon and planets. You should select
A. an objective lens with a long focal length and an eyepiece lens with an even longer focal length.
B. an objective lens with a long focal length and an eyepiece lens with a shorter focal length.
C. an objective lens with a short focal length and an eyepiece lens with a longer focal length.
D. an objective lens with a short focal length and an eyepiece lens with an even shorter focal length.

23. You are designing a telescope that will use a single lens.
Q34.12
You are designing a telescope that will use a single lens.
The purpose of the telescope is to take photographs of the Moon.
The linear magnification m of the image will be in the range
A. m > 1.
B. 0 < m < 1.
C. –1 < m < 0.
D. m < –1.
Answer: C

24. A34.12
You are designing a telescope that will use a single lens.
The purpose of the telescope is to take photographs of the Moon.
The linear magnification m of the image will be in the range
A. m > 1.
B. 0 < m < 1.
C. –1 < m < 0.
D. m < –1.