SAT Physics Practice Test: Optics

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Question 10 questions

Time 8 minutes

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1. What is the wavelength of an X-ray whose frequency is 1.0 × 1018 Hz?

A. 3.3 × 10–11 m
B. 3.0 × 10–10 m
C. 3.3 × 10–9 m
D. 3.0 × 10–8 m
E. 3.0 × 1026 m

2. In Young’s double-slit interference experiment, what is the difference in path length of the light waves from the two slits at the center of the first bright fringe above the central maximum?

A. 0
B. λ
C. λ
D. λ
E. λ

3. A beam of light in air is incident upon the smooth surface of a piece of flint glass, as shown

If the reflected beam and refracted beam are perpendicular to each other, what is the index of refraction of the glass?

D. 2
E. 2

4. When green light (wavelength = 500 nm in air) travels through diamond (refractive index = 2.4), what is its wavelength?

A. 208 nm
B. 357 nm
C. 500 nm
D. 700 nm
E. 1,200 nm

5. A beam of light traveling in medium 1 strikes the interface to another transparent medium, medium 2. If the speed of light is less in medium 2 than in medium 1, the beam will

A. refract toward the normal
B. refract away from the normal
C. undergo total internal reflection
D. have an angle of reflection smaller than the angle of incidence
E. have an angle of reflection greater than the angle of incidence

6. If a clear liquid has a refractive index of 1.45 and a transparent solid has an index of 2.90 then, for total internal reflection to occur at the interface between these two media, which of the following must be true?

incident beam originates in     at an angle of incidence greater than

A. (A) the solid          30°
B. (B) the liquid          30°
C. (C) the solid          60°
D. (D) the liquid          60°
E. (E) Total internal reflection cannot occur.

7. An object is placed 60 cm in front of a concave spherical mirror whose focal length is 40 cm. Which of the following best describes the image?

Nature of image     Distance from mirror

A. (A) Virtual          24 cm
B. (B) Real          24 cm
C. (C) Virtual          120 cm
D. (D) Real          120 cm
E. (E) Real          240 cm

8. An object is placed 60 cm from a spherical convex mirror. If the mirror forms a virtual image 20 cm from the mirror, what’s the magnitude of the mirror’s radius of curvature?

A. 7.5 cm
B. 15 cm
C. 30 cm
D. 60 cm
E. 120 cm

9. The image created by a converging lens is projected onto a screen that’s 60 cm from the lens. If the height of the image is the height of the object, what’s the focal length of the lens?

A. 36 cm
B. 45 cm
C. 48 cm
D. 72 cm
E. 80 cm

10. Which of the following is true concerning a bi-concave lens?

A. Its focal length is positive.
B. It cannot form real images.
C. It cannot form virtual images.
D. It can magnify objects.
E. None of the above