# MCAT Physics Practice Test 8: Light and Optics

### Test Information

15 questions

minutes

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1. If a light ray has a frequency of 5.0 × 1014 Hz, in which region of the electromagnetic spectrum is it located?

• A. X-ray
• B. UV
• C. Visible
• D. Infrared

2. A child stands between two mirrors with his arms out, perpendicular to the mirrors. One plane mirror is 5 m away from his left hand and another plane mirror is 7 m away from his right hand. How far apart are the two images produced by the mirrors if the child has an arm span of 0.5 m?

• A. 2 m
• B. 12 m
• C. 12.5 m
• D. 24.5 m

3. An object is placed at the center of curvature of a concave mirror. Which of the following is true about the image?

• A. It is real and inverted.
• B. It is virtual and inverted.
• C. It is virtual and upright.
• D. It is real and upright.

4. When monochromatic light is refracted as it passes from air to glass, which of the following does NOT remain the same? (Note: Assume that the wave is fully transmitted.)

• A. Wavelength
• B. Frequency
• C. Amplitude
• D. Period

5. A ray of light (f = 5 × 1014 Hz) travels from air into crystal into chromium. If the indices of refraction of air, crystal, and chromium are 1, 2, and 3, respectively, and the incident angle is 30°, then which of the following describes the frequency and the angle of refraction in the chromium?

• A. 5 × 1014 Hz; 9.6°
• B. 5 × 1014 Hz; 57°
• C. 1.0 × 1010 Hz; 9.6°
• D. 1.0 × 1010 Hz; 57°

6. A source of light (f = 6.0 × 1014 Hz) passes through three plane polarizers. The first two polarizers are in the same direction, while the third is rotated 90° with respect to the second polarizer. What is the frequency of the light that comes out of the third polarizer?

• A. Light will not pass through the third polarizer
• B. 3.0 × 1014 Hz
• C. 6.0 × 1014 Hz
• D. 9.0 × 1014 Hz

7. Which phenomenon would cause monochromatic light entering the prism along path AB to leave along path CD?

• A. Dispersion
• B. Refraction
• C. Diffraction
• D. Polarization

8. Which of the following describes the image formed by an object placed in front of a convex lens at a distance smaller than the focal length?

• A. Virtual and inverted
• B. Virtual and upright
• C. Real and upright
• D. Real and inverted

9. A submarine is inspecting the surface of the water with a laser that points from the submarine to the surface of the water and through the air. At what angle will the laser not penetrate the surface of the water but rather reflect entirely back into the water? (Assume nwater = 1.33 and nair = 1.)

• A. 19°
• B. 29°
• C. 39°
• D. 49°

10. A student is analyzing the behavior of a light ray that is passed through a small opening and a lens and allowed to project on a screen a distance away. What happens to the central maximum (the brightest spot on the screen) when the slit becomes narrower?

• A. The central maximum remains the same.
• B. The central maximum becomes narrower.
• C. The central maximum becomes wider.
• D. The central maximum divides into smaller light fringes.

11. Which of the following are able to produce a virtual image?

I. Convex lens

II. Concave lens

III. Plane mirror

• A. I only
• B. III only
• C. II and III only
• D. I, II, and III

12. Monochromatic red light is allowed to pass between two different media. If the incident angle in medium 1 is 30° and the incident angle in medium 2 is 45°, what is the relationship between the speed of the light in medium 2 compared to that in medium 1?

• A.
• B.
• C.
• D.

13. A scientist looks through a microscope with two thin lenses with m1 = 10 and m2 = 40. What is the overall magnification of this microscope?

• A. 0.25
• B. 30
• C. 50
• D. 400

14. Imagine that a beam of monochromatic light originates in air and is allowed to shine upon the flat surface of a piece of glass at an angle of 60° with the normal. The reflected and refracted beams are perpendicular to each other. What is the index of refraction of the glass?

• A.
• B. 1
• C. 2
• D.

15. Which of the following will not result in the splitting of white light into its component colors?

• A. Dispersion through a prism
• B. Diffraction through a grating
• C. Refraction within a thin film
• D. Reflection from an ideal convex mirror

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