Diffraction and Optical resolution Quiz

1 / 10

1. A human eye has a pupil diameter of exactly 3.0 mm and is viewing a point source of light with a wavelength of 555 nm. According to the Rayleigh criterion, what is the minimum angular separation (in radians) required between two point sources for the eye to just resolve them as separate objects?

1. 1.85 × 10⁻⁴ rad

2. 2.26 × 10⁻⁴ rad

3. 1.85 × 10⁻⁷ rad

4. 2.26 × 10⁻⁷ rad

2 / 10

2. Which of the following alterations will simultaneously decrease the amount of diffraction blurring occurring inside an optical scanning device?

1. Increasing the wavelength of light and decreasing the lens diameter

2. Decreasing the wavelength of light and increasing the lens diameter

3. Increasing both the wavelength of light and the lens diameter

4. Decreasing both the wavelength of light and the lens diameter

3 / 10

3. A diffraction grating contains exactly 500 lines per millimeter. When a beam of light passes through the grating, at what angle relative to the incident beam will the first-order (m = 1) maximum appear for a wavelength of 600 nm?

1. 11.5°

2. 17.5°

3. 30.0°

4. 42.1°

4 / 10

4. Monochromatic light from a helium-neon laser (λ = 632.8 nm) passes through a single vertical slit with a width of 0.10 mm and projects a diffraction pattern onto a screen 1.5 meters away. What is the total linear width of the central bright maximum on the screen?

1. 4.7 mm

2. 9.5 mm

3. 19.0 mm

4. 28.5 mm

5 / 10

5. A camera lens with an f-number of f/4 (which implies the focal length divided by the aperture diameter is 4) captures an image using light with a wavelength of 500 nm. What is the physical linear radius of the resulting Airy disc projected onto the digital sensor chip?

1. 1.22 μm

2. 2.44 μm

3. 4.88 μm

4. 9.76 μm

6 / 10

6. A single-slit diffraction setup is submerged completely in a specialized fluid medium with a refractive index of n = 1.40. If the initial width of the central maximum on the screen in air was 14.0 mm, what will the new width of this central bright zone become inside the liquid?

1. 10.0 mm

2. 14.0 mm

3. 19.6 mm

4. 28.0 mm

7 / 10

7. Under the Rayleigh criterion for a circular aperture, the first diffraction minimum occurs at a specific spatial location relative to the central peak. This exact boundary condition occurs when the path difference between light rays originating from opposite edges of the circular opening equals which value?

1. 0.50 λ

2. 1.00 λ

3. 1.22 λ

4. 2.00 λ

8 / 10

8. An astronomical telescope utilizes an objective lens with a diameter of 10.0 cm to view a binary star system emitting light at a wavelength of 500 nm. What is the theoretical resolving power (minimum angular separation in arcseconds) of this telescope?

1. 1.26"

2. 2.52"

3. 0.13"

4. 6.10"

9 / 10

9. A laboratory spectrometer uses a diffraction grating to resolve two closely spaced spectral lines at λ = 589.0 nm and λ = 589.6 nm. According to the chromatic resolving power criteria (R = λ/Δλ = mN), what is the minimum number of total lines (N) that must be illuminated on the grating to separate these lines in the first-order (m = 1) spectrum?

1. 589 lines

2. 982 lines

3. 1,178 lines

4. 3,534 lines

10 / 10

10. If a patient’s pupil constricts from 6.0 mm down to 2.0 mm under bright lighting conditions, how does this physiological change impact the diffraction-limited resolution of the retinal image?

1. The angular resolution limit decreases by a factor of 3, improving image detail.

2. The angular resolution limit increases by a factor of 3, degrading theoretical detail.

3. The angular resolution limit decreases by a factor of 9, improving image detail.

4. The angular resolution limit increases by a factor of 9, degrading theoretical detail.

Your score is

Optometry Skills

Optometry education for Optometry students and eye care professionals. Managed by qualified optometrists. For informational purposes only — not a substitute for professional eye care.