Question 40 (Textile Engineering & Fibre Science)
The contraction of a yarn upon twisting is 1.07. The twisted yarn count is 30 tex. If 2 dtex fibres are used to produce the yarn, the number of fibres present in yarn cross-section is
| (A) | 140 |
| (B) | 145 |
| (C) | 150 |
| (D) | 160 |
[Show Answer]
Option A is correct.
Twist contraction=1.07
The twisted yarn count=30tex
Count of fibres=2 dtex
=0.2 tex
Let,the number of fibres present in yarn cross-section=N
Then, Untwisted count of yarn=N x 0.2
The number of fibres present in yarn cross-section=?
By formula-
Twist contraction=Untwisted length/twisted length
1.07=Twisted count/Untwisted count
1.07=30/N x 0.2
1.07 x N=30/0.2
N=30/(0.2 x 1.07)
N=140.18
N=140 (Ans)