Anna University Physical Structure and Properties of Fibers Model Test Paper
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 ´ 2 = 20 marks)
1.What are the requirements of a polymer to form Textile fiber?
2.Write the chemical structure of Polyester and Nylon 6,6.
3.State the application of Electron Microscopy in the field of textiles.
4.What are the differences between X–ray and electron microscopic studies?
5.State the significance of moisture absorption in textile field.
6.Establish the relation between moisture regain and relative humidity.
7.Define the terms – (a) tenacity and (b) work of rupture.
8.How do you determine the torsional rigidity of a fiber?
9.What is the difference between static and kinetic friction?
10.What are the factors that influence the electrical resistance of fibers?
PART B — (5 ´ 16 = 80 marks)
11.(i) What is breaking load of fibers?
(ii) What is breaking extension of a fiber?
(iii) Differentiate between breaking load and Tenacity.
(iv)Define the term stress relaxation.
(v)Why does different textile fibers have different Stress–strain curve?
(vi)Distinguish between Elastic extension and Elastic recovery.
(vii) What is Creep?
(viii) List out the factors that affect the tensile properties of textiles fibers.
(each 2 marks)
12.(a)With a neat sketch explain the physical and morphological structure of cotton fibers.
(b)The mechanical properties of a fiber is influenced by its molecular structure. Explain in detail.
13.(a)Explain the use of X–ray diffraction methods in studying the fiber structure.
(b)Discuss the use of polarizing microscope for the study of fiber structure.
14.(a)Explain with suitable examples the hygroscopic nature of fibers. What is the effect of temperature and stress on the above?
(b)Explain the phenomenon of conditioning in textile fibers. What are the factors that influence the conditioning process?
15.(a)Explain the following terms :
(i) Dielectric potential
(ii) Electrical resistance.
(b)Discuss in detail, the measurement of friction of yarns and fabric. What is the effect of friction on processability of fibers?