Question

Question 22:

Polyster fabric is lustrous, while cotton is not. Luster depends on the way light is reflected by

the fibre and is determined by its cross-sectional shape. Luster is an important aesthetic

property related to the reflection of light. For example, Silk is highly lustrous due to uniform

cross-sectional area of its fiber. Luster results from the way light is reflected from a surface.

The more lustrous a fiber, the more evenly does it reflects the incident light. Thus, the crosssectional shapes which can reflect the incident light most evenly will give a strong luster. But, when the fiber or filament is twisted upon itself in the yarn and fabric, the incident light is not

reflected as evenly and it results in a softer luster.

The cross-sectional shapes of various fibres are given below. Which one of the following is

most likely the cross-sectional shape of a cotton fibre?

A.

B.

C.

D​
answer rapidly

Answer 1

Answer:

C

Explanation:

The cross-section of a cotton fibre is often described as being kidney-shaped.

Answer 2

Answer:

option c

iam telling this answer very confidently becoz iam also writing this pisa test