GATE

Q. The experimentally determined density of a fibre is 1.31 g/cc. If the density of the void free fibre is 1.35 g/cc, then the void volume fraction (%) of the fibre sample (rounded off to 2 decimal places) is       . Ans: 2.60-3.00

Q. In melt spinning, the diameter of monofilament at the spinneret exit is 0.3 mm and at the take-up point is 0.15 mm. Assuming that there is no change in density of filament, the spin- draw ratio is . Ans: 4-4

Q. Determine the correctness or otherwise of the following Assertion [a] and Reason [r] [a] : Synthetic thickeners used in pigment printing are neutralized before printing. [r] : Without neutralization, the viscosity required for printing would not be achieved. (A) Both [a] and [r] are true and [r] is the correct reason for [a] (B)

Q. The set containing oxidative bleaching agents only is P. Sodium hydrosulphite Q. Thiourea dioxide R. Sodium hypochlorite S. Hydrogen peroxide (A) P and Q (B) Q and R (C) R and S (D) P and S Ans: (C) R and S

Q. The correct combination of reasons, which leads to decrease in tear strength of a woven fabric, is P. Increase in yarn to yarn friction Q. Decrease in yarn to yarn friction R. Increase in fabric sett S. Decrease in fabric sett (A) P and R (B) P and S (C) Q and R (D)

Q. In air-jet weaving, the correct combination of parameters, on which drag force on weft yarn depends, is P. Weave pattern       Q. Density of air          R. Weft yarn diameter S. Picks per cm (A) P and Q                      (B) Q and R               (C) R and S               (D) P and S Ans: Q and R

Q. The punch density of a needle-punched nonwoven fabric is 50 punches/cm2. If the stroke frequency of needle bed is doubled and the fabric delivery speed is halved, then the punch density (punches/cm2) would be (A) 25 (B) 50 (C) 100 (D) 200 Ans: 200

Q. Determine the correctness or otherwise of the following Assertion [a] and the Reason [r] [a] : The short term mass irregularity of rotor yarn is less than that of ring yarn. [r] : Rotor yarn has belt or wrapper fibres, but ring yarn does not.  (A) Both [a] and [r] are true and [r]

Q. A drawframe with a 3 over 3 drafting arrangement, having an eccentric bottom middle roller of 28 mm diameter, is used to produce a sliver. The back zone and front zone drafts are 1.7 and 3.5, respectively. The sliver is further given a draft of 200 to produce a yarn. The wavelength (m) of

Q. An opening roller in blowroom with 100 cm length, 38 cm diameter and 2 teeth per cm2 is rotating at an angular velocity of 400 rpm to deliver fibre tufts at a production rate of 500 kg/h. The intensity of opening (fibre mass in mg per tooth) of the opening roller approximately is (A)