List of practice Questions

Three monodisperse Nylon 6 samples with molar masses 10000 g/mol, 30000 g/mol and 60000 g/mol are mixed in a proportion of 1:1:2 by number of chains. The polydispersity index of the resulting sample (rounded off to 2 decimal places) is .................

Amongst the Classimat faults A2, B1, D4, H2 and I1, the correct statement(s) is/are

A sample of cotton fabric is dyed with a vat dye at 60°C till equilibrium dye uptake is reached. Another sample of the same cotton fabric is dyed with the same dye at 90°C till equilibrium, keeping all other parameters same. Amongst the following, the correct statement(s) is/are:

In pigment printing of cotton fabric, the pigment (along with binder) can be fixed by using:

Drafting force in drawframe, when fibres are sliding, reduces with higher

The force exerted by the reed on the cloth-fell at the instant of beat-up (weaving resistance) depends on

With reference to KES-FB and FAST systems, the same low stress mechanical property is measured by

With reference to the work factor (WF) and work of rupture (WR) of two yarns with the same breaking load and the same breaking elongation, the correct statement(s) is/are

Determine the correctness or otherwise of the following Assertion [a] and Reason [r] [a]: MgCl$_2$ is used in the formulation of anti-crease finishing of cotton fabric with DMDHEU.
[r]: MgCl$_2$ is an acidic salt and acts as a catalyst.

Determine the correctness or otherwise of the following Assertion [a] and Reason [r]:
[a]: A partially scoured cotton fabric bleached with H$_2$O$_2$ exhibits higher water absorbancy than that bleached with NaClO$_2$.
[r]: Bleaching with H$_2$O$_2$ also facilitates scouring.

In wet spinning of acrylic fibres

Consider the following activities on a carding machine:
P. Lowering surface speed of feed roller
Q. Increasing rotational speed of taker-in
R. Increasing linear density of feed material
S. Use of shorter and finer fibres
The correct combination of the above activities to obtain more number of taker-in teeth acting per fibre is .................

Consider the following statements with regard to the timing diagram of a cotton combing machine.
P. In forward feed system, feeding mostly takes place when nippers are closing
Q. Cylinder comb starts combing after feeding ends
R. Detaching rollers move backward during forward movement of nipper assembly
S. Top comb is not combing when detaching rollers move forward
The correct combination of TRUE statements is:

Consider the following reasons of shuttle loom stoppage. P. Breakage of warp yarns
Q. Entrapment of shuttle inside the shed
R. Flying of shuttle out of the shed
S. Slackening of a warp yarn
The correct combination that triggers the warp protector motion is

In warp knitting, the lapping movement having only under-lap is

Consider the following statements regarding Nylon 6 production from caprolactam using water as a catalyst.
[(P)] The first reaction involving ring-opening of caprolactam with water is an endothermic reaction.
[(Q)] Increase in water concentration during the polycondensation results in a higher molecular weight polymer
[(R)] The polycondensation is an irreversible reaction
[(S)] Increase in temperature during the polycondensation results in a lower molecular weight polymer.
The correct combination of TRUE statements is

Determine the correctness or otherwise of the following Assertion [a] and Reason [r].
[a]: In boiling water, polyester POY shows higher shrinkage than polyester FDY.
[r]: Molecular chain orientation is higher in polyester FDY than polyester POY.

A ring spun yarn with mean linear density of 32 tex is produced from 2 denier polyester staple fibre. If the standard deviation of the yarn linear density is 3.2 tex, then the index of irregularity of the yarn (up to 1 decimal place) is:

A cotton fabric is to be dyed with 2 % shade (on the weight of fabric). If dye concentration is 0.4 g/L, then the material-to-liquor ratio is 1 : X. The value of X (in integer) is

Two vertical poles of height 6 m and 18 m are 10 m apart on a flat ground. A string needs to be connected from the top of one pole to a peg on the ground and then on to the top of the other pole. The minimum length (m) of the string is

A PET sample with 40% crystallinity shows only a melting endotherm in the first heating cycle of DSC with a melting enthalpy of 50 J/g. The degree of crystallinity (%) of another PET sample which also shows only a melting endotherm but with a melting enthalpy of 80 J/g is (in integer) .................

If the twist multiplier in the indirect system is 4.8 tpi/Ne\(^{0.5}\), then the twist factor in the direct system (tpm tex\(^{0.5}\)) (rounded off to 2 decimal places) is ................

A plain woven fabric with 20 ends per cm and 30 picks per cm is prepared with 30 tex warp yarns and 25 tex weft yarns. Neglecting yarn crimp, the areal density (g/m\(^2\)) of the fabric (in integer) is:

The Newton-Raphson method is being used for two iterations to find an approximate solution of the equation \( e^x - 1 = 0 \) with an initial guess of 1. The difference between the actual and approximate solutions (rounded off to 2 decimal places) is .................

The area under the curve \( y = x^2 + 2x \) between \( x = 0 \) and \( x = 4 \), using the trapezoidal rule with a step size of one, (in integer) is .................