Download GTU B.Tech 2020 Winter 7th Sem 2172904 Yarn Structure And Fabric Geometry Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 7th Sem 2172904 Yarn Structure And Fabric Geometry Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?VII (NEW) EXAMINATION ? WINTER 2020
Subject Code:2172904 Date:25/01/2021
Subject Name:Yarn Structure & Fabric Geometry
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) Define the terms: a) Twist b) Twist multiplier
03

(b) State role of yarn structure on yarn and fabric properties
04

(c) Derive the equation: tan = 0.0112 Vy ? .
07


Q.2 (a) What do you mean by twist contraction and retraction factor?
03

(b) State phenomenon of Crimp interchange.
04

(c) Derive the equations to calculate warp cover factor & weft cover factor.
07




Q.3 (a) State classification of yarn.
03

(b) Draw figure of idealized twist geometry and derive five basic equations.
04

(c) Describe the disturbing factors that operate in determining real yarn 07
structures.




Q.4 (a) Define with reference to migration:
03
a) Mean fibre position ( ) b) RMS deviation (D),

(b) Explains Hamilton ? Coil winding method of measuring yarn diameter.
04

(c) Derive the Retraction factor, Ry = tan2 (/2).
07
Q.5 (a) State importance of cloth cover.
03

(b) Find the cloth cover if warp count & epi is 30's & 62 respectively and weft 04
count & ppi is 24's & 46 respectively.

(c) Establish the relationship between k & d/p for maximum cover.
07



Q.6 (a) Discuss about modulus of elasticity.
03

(b) What do you mean by Fractional cover of warp and weft?
04

(c) Explain the geometry of jammed condition for Race track cross-section.
07
Q.7 (a) Define with reference to fabric: a) Isotropic, b) Anisotropic.
03

(b) Give limitation of fabric geometrical model.
04

(c) Derive the equations for Pierce's model for the geometry of Plain woven 07
fabric when "Neither of the yarn is straight nor it is jammed.



Q.8 (a) Define the terms: Poisson ratio.
03
(b) Explain load-extension curve for the woven fabric showing different zones.
04
(c) Described the factors that influence yarn tensile properties.
07

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