Question

which of these images is the most likely to have a trilobal cross-section?

select one:
a. a
b. b
c. c
d. d
e. e

Explanation:

Identify fiber types

The image displays five different fibers labeled A through E under microscopic view.

• A shows longitudinal striations characteristic of synthetic fibers like nylon or acetate.
• B and C show distinct internal structures (medullae), which are characteristic of animal hairs (e.g., Animal Hair Morphology).
• D shows a highly patterned, overlapping surface structure characteristic of wool (scales).
• E shows a smooth, uniform synthetic fiber.

Analyze trilobal cross-section

A trilobal cross-section is a common engineered shape for synthetic fibers, especially nylon.

• When viewed longitudinally under a light microscope, a trilobal fiber (like nylon) displays distinct, parallel longitudinal shadow lines or striations running along its length due to its three-lobed geometry reflecting light.
• Fiber A clearly shows these characteristic longitudinal striations/lines along its shaft, indicating a non-round, multi-lobed (trilobal) cross-section.
• Therefore, fiber A is the most likely to have a trilobal cross-section.

Answer:

• a. A (Correct answer)
• b. B
• c. C
• d. D
• e. E