List of practice Questions

A hammer mill is used to grind blackgram. The size distribution is such that 80% passes through a 6-mesh (3.36 mm) screen. The power required to produce a powder where 80% passes through a 45-mesh (0.354 mm) screen is 4.5 kW. Find the power in kW required to produce a finer powder, 80% of which passes through a 60-mesh (0.25 mm) screen. Use Bond’s law of size reduction.

If $D_{10}$ for {Salmonella} in egg yolk is 0.75 kGy, calculate the radiation dose in kGy (rounded off to 2 decimal places) required for reducing the {Salmonella} count in egg yolk by 8 log cycles.

The average moisture binding energy of a plant protein-based snack at 8% moisture content (dry basis) is 3200 cal.mol$^{-1}$. If the water activity of the snack at the above moisture content is 0.30 at 30°C, the water activity of the sample at 45°C is ............. (rounded off to 2 decimal places). Use $R = 1.987$ cal.mol$^{-1}$.K$^{-1}$.

Cow milk is pasteurized at a flow rate of 1 kg.s$^{-1}$ in a counter-current heat exchanger using hot water as the heating medium. The milk enters at 15°C and exits at 50°C. The specific heat of milk is 3.5 kJ.kg$^{-1}$.°C$^{-1}$. Hot water enters at 75°C and exits at 60°C. Overall heat transfer coefficient $U = 1800$ W.m$^{-2}$.°C$^{-1}$. Find the heat transfer surface area in m$^2$ (rounded off to 2 decimal places). Assume steady-state.

The net water level elevation near the coast arising due to a tropical-cyclone-induced storm is a combination of the following factors ................

The typical speeds of a tsunami wave in water depths of 10 m, 100 m, and 1000 m, respectively, are ................

Match the enzyme in Column I with its application in food processing/reaction given in Column II.

Identify the Gram +ve bacteria responsible for causing food borne diseases among the following.

Extrusion cooking is accomplished in four different stages (I, II, III, IV). Identify the correct order from the given options.

Match the method/value used for measuring lipid characteristics in Column I with the corresponding properties indicated by them, in Column II.

Identify the correct statement(s) related to grain polysaccharides among the followings.

Which among the followings is NOT an essential amino acid?

The time required for stipulated destruction of a microbial population at a given temperature is ______.

Which among the following statements is NOT correct?

Which of the following statements is NOT correct?

Calculate the efficiency in percent (rounded off to 1 decimal place) of an oil expeller which yields 37 kg oil containing 5% solid impurities from 100 kg mustard seeds. The oil content of the mustard seed is 38%.

Orange juice is packaged aseptically and stored under ambient conditions. The degradation of vitamin C in the juice occurs during storage following first-order reaction kinetics. The degradation rate constant is $5.2 \times 10^{-3}$ day$^{-1}$. The half-life of vitamin C in days is ............. (in integer).

The weight of 10 kg dried cauliflower containing 5% moisture (wet basis) after rehydration is 60 kg. If the fresh cauliflower contained 87% moisture (wet basis), calculate the coefficient of rehydration (rounded off to 2 decimal places).

Match the industrial product in Column I with the fermentative organism in Column II.

A nylon sample of 0.03 m$^2$ cross-sectional area is subjected to a creep load of 10 kN. The load is removed after a duration of 60 s. Young’s modulus and the viscosity for nylon are 1 GPa and 300 Giga Poise. The compliance of the specimen is ______ $\times 10^{-9}$ m$^2$/N.

PVDF was quenched in one case and slowly cooled at 10$^\circ$C/min in another case. The crystallinity of slowly cooled PVDF = 60%. The heat of fusion of the quenched PVDF = 0.54 $\Delta H_m$ (where $\Delta H_m$ = heat of fusion of slowly cooled PVDF). Heat of fusion of 100% crystalline PVDF = 100 J/g. Find crystallinity of quenched PVDF.

Density = 0.9 g/cc, melt volume = 10 cc, residence time = 100 s. Find extruder output in kg/h.

Polymer 0.2 g in 100 mL benzene. Relative viscosity = 1.5. Mark–Houwink: $[\eta] = K M^a$ with $a=0.5$, $K=0.001$. Find molecular weight.

Glass-fiber composite: 40% glass fibers ($E_f = 69$ GPa), 60% polyester resin ($E_m=3.4$ GPa). Find modulus of elasticity of composite in longitudinal direction.

Choose the correct group of fat-soluble vitamins.