6. Optical properties of gemspolarization of light

Welcome to your Module 6 - Optical properties of gemspolarization of light/Nature of Polarized Light

1. What characterizes polarized light?

1. Nature of Polarized Light

A) Light with waves oscillating in random planes

B) Light with waves oscillating in the same plane

C) Light with waves oscillating in perpendicular planes

D) Light with waves oscillating in parallel planes

2. How is polarized light created?

A) By passing light through a prism

B) By passing light through a polarizing filter

C) By heating light waves

D) By cooling light waves

3. Which type of light consists of waves vibrating in a single plane?

A) Unpolarized light

B) Monochromatic light

C) Polarized light

D) Incoherent light

4. What is the key characteristic of unpolarized light?

A) Waves vibrating in a single plane

B) Waves vibrating in multiple planes

C) Waves vibrating in a circular motion

D) Waves vibrating in a straight line

5. In which type of crystal do optic axes exist?

2. Optic Axes

A) Isotropic crystals

B) Cubic crystals

C) Anisotropic crystals

D) Hexagonal crystals

6. How many optic axes do biaxial crystals have?

A) None

B) One

C) Two

D) Three

7. What is the primary characteristic of uniaxial crystals?

A) They have two optic axes

B) They have one optic axis

C) They have three optic axes

D) They have no optic axes

8. Which type of crystal has a single, unique refractive index?

A) Uniaxial crystals

B) Biaxial crystals

C) Isotropic crystals

D) Cubic crystals

9. What is a defining property of isotropic materials?

3. Isotropic and Anisotropic Behavior

A) They have one refractive index

B) They have multiple refractive indices

C) They exhibit double refraction

D) They are opaque

10. Which gemstone property refers to having the same optical properties in all directions?

A) Isotropic

B) Anisotropic

C) Pleochroism

D) Birefringence

11. Which type of gemstone material exhibits double refraction?

A) Isotropic

B) Anisotropic

C) Cubic

D) Opaque

12. What causes the phenomenon of pleochroism in gemstones?

A) Double refraction

B) Isotropic behavior

C) Anisotropic behavior

D) Variable transparency

13. How is polarized light produced using polaroid filters?

4. The Production of Polarized Light

A) By reflecting light at an angle

B) By scattering light through particles

C) By absorbing light vibrating in specific directions

D) By emitting light waves in a single direction

14. What type of light is produced when light reflects off a nonmetallic surface at Brewster's angle?

A) Isotropic light

B) Polarized light

C) Anisotropic light

D) Monochromatic light

15. Which optical phenomenon is responsible for polarizing light using birefringent crystals?

A) Diffraction

B) Interference

C) Dispersion

D) Double refraction

16. How does a polariscope produce polarized light?

A) By using a single polarizing filter

B) By using a light source and a mirror

C) By using a polarizer and an analyzer

D) By using a lens and a prism

17. What is the function of a polarizing filter?

5. The Polarizing Filter

A) To absorb all light waves

B) To scatter light waves

C) To allow only light vibrating in a specific direction to pass through

D) To change the color of light waves

18. What material are polarizing filters commonly made from?

A) Diamond

B) Quartz

C) Polaroid

D) Glass

19. Which type of polarizing filter is used in photography to reduce glare?

A) Linear polarizer

B) Circular polarizer

C) Birefringent polarizer

D) Dichroic polarizer

20. How does a circular polarizer differ from a linear polarizer?

A) It absorbs light waves

B) It changes the direction of light waves

C) It converts linearly polarized light into circularly polarized light

D) It reflects light waves

21. What is the main component of a polariscope?

6. Construction, Uses, and Typically Results of Polariscope

A) A light source

B) A mirror

C) A prism

D) A polarizer and an analyzer

22. How does a polariscope determine if a gemstone is isotropic or anisotropic?

A) By rotating the gemstone and observing changes in light patterns

B) By heating the gemstone and observing color changes

C) By cooling the gemstone and observing cracks

D) By applying pressure to the gemstone and observing fractures

23. What are interference figures used to identify in gemstones?

A) The number of inclusions

B) The type of metal

C) The optic axes

D) The color spectrum

24. What is an interference figure in gemology?

A) A visual pattern used to detect polarized light

B) A pattern used to measure the weight of a gemstone

C) A pattern used to identify the crystal structure

D) A pattern used to calculate the age of a gemstone

25. What type of crystal is indicated by a uniaxial interference figure?

7. Interference Figures

A) A crystal with one optic axis

B) A crystal with two optic axes

C) A crystal with three optic axes

D) A crystal with no optic axes

26. What is an interference figure used to examine?

A) The color of a gemstone

B) The purity of a gemstone

C) The optical properties of a gemstone

D) The age of a gemstone

27. What is the main purpose of a conoscope in a polariscope?

A) To adjust the focus

B) To rotate the gemstone

C) To capture images

D) To observe interference patterns

28. What does a biaxial interference figure typically resemble?

A) A Maltese cross

B) A circle

C) A square

D) A star

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