List of top Questions asked in GATE XE

Which of the following pigments does NOT have pro-vitamin A activity?
Identify the analysis that must be performed FIRST to judge ‘cleanliness’ of spice/herb powders.
If there is a delay in oil extraction after bran is separated from the brown rice, the quality of rice bran oil deteriorates. Identify the suitable CAUSE and EFFECT for the deterioration in oil quality.
Among the following, which is/are the process(es) that lead to generation of new fats from existing ones?
The true density and bulk density of wheat grains are 1280 kg/m\(^3\) and 740 kg/m\(^3\), respectively. The porosity of the grains is ................ (rounded off to 2 decimal places).
The crystallization of a polymer can only proceed in a temperature range limited to glass transition temperature (\(T_g\)) on the lower side and the equilibrium melting point (\(T_m^0\)) on the higher side. In a miscible polymer blend with only one component being crystalline, which option(s) correctly match(es) the Temperature conditions with Events? \[ \begin{array}{|c|c|} \hline \text{Temperature conditions} & \text{Events}
\hline P: T_g \text{ of amorphous component<crystallizable one} & 1: \text{Temperature range for crystallization becomes smaller}
Q: T_g \text{ of amorphous component>crystallizable one} & 2: \text{Crystallization is inhibited}
R: T_g \text{ of blend>} T_m^0 \text{ of crystallizable one} & 3: \text{Crystallization envelope (}T_m^0 - T_g\text{) is widened}
& 4: \text{Crystallization is favored}
\hline \end{array} \]
The heat of polymerization of ethylene is 25 Kcal/mol. The amount of heat generated during the polymerization of 5.6 kg polyethylene is .............. Kcal. (Round off to the nearest integer)
The density of an amorphous polymer is 0.77 g/cm\(^3\) and that of its crystalline counterpart is 0.99 g/cm\(^3\). The density of a semi-crystalline sample of this polymer is 0.88 g/cm\(^3\). Find the degree of crystallinity (on weight basis) of this semi-crystalline sample. (Round off to two decimal places)
Titration was used to determine the molar mass of two linear monodisperse polymers A and B. Both polymers have the same repeat unit and contain acid end-groups. - 10 g of polymer A titrated with 5 mL of 0.1 M alkali solution. - 5 g of polymer B titrated with 5 mL of 0.1 M alkali solution. - All alkali reacted with acid end-groups. Find the ratio of the molar mass of A to that of B. (Round off to one decimal place)
A unidirectional composite of a resin is prepared with continuous fibers, with volume fraction of fiber = 0.7. Moduli: resin = 9 GPa, fiber = 90 GPa. Sample breadth = 4 mm, thickness = 1 mm. Tensile strain = 0.5%. Find the tensile force applied on the sample. (Round off to nearest integer)
A rubber contains 70 wt% butadiene (molar mass = 54 g/mol), 20 wt% isoprene (molar mass = 68 g/mol), 5 wt% sulfur and 5 wt% carbon black. Assume that all the sulfur is present in crosslinks. If each sulfide crosslink contains an average of two sulfur atoms, the percentage of possible crosslinks that are joined by vulcanization is ........................%. (Round off to one decimal place)
Which of the following contains the phytonutrient allicin?
Which mold is responsible for the characteristic blue marbling in blue-veined cheese?
The ‘unperturbed dimension’ of the polymer chain is represented as, \[ \left( \overline{r_0^2} \right)^{1/2} \propto \bar{l}\,(n)^{1/2} \] where, \(\left( \overline{r_0^2} \right)^{1/2}\) = root-mean-square end-to-end distance
\(\bar{l}\) = average length of a segment
\(n\) = number of segments in the chain Using the above information, root-mean-square end-to-end distance of a branched polyethylene would be ........... when compared with that of the linear polyethylene of the same molecular weight and the same number of segments.
Choose the option(s) that correctly match(es) the Zones with their typical Functions in an industrial extruder.
In a polymer recycling plant, polymer “X” was depolymerized by glycolysis in the presence of ethylene glycol and a suitable catalyst. The glycolysis reaction yielded the following compound (a bis-hydroxyethyl ester of terephthalic acid). Identify the polymer “X” from the following options:
Polymer “Z” has a high melting point and it decomposes even before it melts. Hence, it is usually dissolved and subsequently regenerated. Rayon is one such regenerated form. Identify the polymer “Z” from the following options.
Match the Product with the most appropriate Processing Technique employed.
Crystallization is favored in polymer melts when the chain entanglement is ............ and only polymers with .................. molecular arrangement can crystallize.
Match the Polymer with the most suitable Monomer combinations from which it is synthesized. \[ \begin{array}{|c|c|} \hline \text{Polymer} & \text{Monomer combinations} \\ \hline P: \text{Polyurethane} & 1: \text{Maleic acid and propylene glycol} \\ Q: \text{Epoxy} & 2: \text{Pyromellitic anhydride and p,p'-diamino diphenyl ether} \\ R: \text{Polyimide} & 3: \text{Epichlorohydrin and bisphenol A} \\ S: \text{Polyester} & 4: \text{Hexamethylene diisocyanate and tetramethylene glycol} \\ \hline \end{array} \]
Thermoplastic Polyurethane and Polyamide 6 both contain amide linkages, but when compared to Polyurethane, Polyamide 6 shows higher melting point due to .................
A steam boiler contains saturated water vapour at 200 °C. After a certain period, the temperature of the boiler drops to 110 °C. Assume that all the valves of the boiler are closed and the energy is lost as heat to the surroundings. The ratio of mass of liquid to the mass of vapour is ............. (rounded off to two decimal places). Data: - \(v_g(200^\circ C) = 0.127 \, m^3/kg\) - \(v_g(110^\circ C) = 1.210 \, m^3/kg\) - \(v_f(110^\circ C) = 0.001 \, m^3/kg\)
Two Carnot heat engines (E1 and E2) are operating in series as shown in figure. Engine E1 receives heat from a reservoir at \(T_H = 1600 \, K\) and does work \(W_1\). Engine E2 receives heat from an intermediate reservoir at \(T\), does work \(W_2\), and rejects the rest to a reservoir at \(T_L = 400 \, K\). Both the engines have identical thermal efficiencies. The temperature \(T\) (in K) of the intermediate reservoir is ............ (answer in integer).
A particular temperature scale is obtained according to the relation: \[ t = a e^{\alpha} + b \] where \(a\) and \(b\) are constants, and \(t\) is in °C. The thermometric property as measured by the thermometer is \(\alpha\). The values of \(\alpha\) at ice point and steam point are 6 and 9, respectively. The temperature (in °C) which gives \(\alpha = 7\) is ................. (rounded off to two decimal places).
In a piston-cylinder assembly, one kmol of an ideal gas is compressed from an initial state of 200 kPa and 400 K to a final state of 1 MPa and 400 K. If the surroundings are at 400 K, the minimum amount of work (in kJ/kmol) required for the compression process is ............... (rounded off to two decimal places). Use: Universal gas constant (\(R_u\)) = 8.314 kJ/kmol-K