GATE AG 2019 Question Paper & Solutions

Verbal Aptitude

The fishermen, ______ the flood victims owed their lives, were rewarded by the government.

Analytical & Spatial Aptitude

Some students were not involved in the strike. If the above statement is true, which of the following conclusions is/are logically necessary? 1. Some who were involved in the strike were students. 2. No student was involved in the strike. 3. At least one student was involved in the strike. 4. Some who were not involved in the strike were students.

Verbal Aptitude

The radius as well as the height of a circular cone increases by 10%. The percentage increase in its volume is ______.

Analytical & Spatial Aptitude

Five numbers 10, 7, 5, 4 and 2 are to be arranged in a sequence left to right following: 1. No two odd or even numbers are next to each other. 2. The second number from the left is exactly half of the left-most number. 3. The middle number is exactly twice the right-most number. Which is the second number from the right?

Verbal Aptitude

Until Iran came along, India had never been ______ in kabaddi.

Analytical & Spatial Aptitude

Since the last one year, after a 125 basis point reduction in repo rate by the RBI, banking institutions have been making a demand to reduce interest rates on small saving schemes. Finally, the government announced yesterday a reduction in interest rates on small saving schemes to bring them on par with fixed deposit interest rates. Which statement can be inferred from the passage?

Verbal Aptitude

In a country of 1400 million population, 70% own mobile phones. Among the mobile phone owners, only 294 million access the Internet. Among these Internet users, only half buy goods from e-commerce portals. What is the percentage of these buyers in the country?

Verbal Aptitude

The nomenclature of Hindustani music has changed over centuries. Since the medieval period dhrupad styles were identified as baanis. Terms like gayaki and baaj were used to refer to vocal and instrumental styles, respectively. With institutionalization of music education the term gharana became acceptable; gharana originally referred to hereditary musicians from a particular lineage, including disciples and grand disciples. Which pairing is NOT correct?

Verbal Aptitude

Two trains started at 7AM from the same point. The first travelled north at 80 km/h and the second travelled south at 100 km/h. The time at which they were 540 km apart is ______ AM.

Analytical & Spatial Aptitude

"I read somewhere that in ancient times the prestige of a kingdom depended upon the number of taxes that it was able to levy on its people. It was very much like the prestige of a head-hunter in his own community." Based on the paragraph, the prestige of a head-hunter depended upon ______.

Calculus

$I = \int_{0}^{\infty} \frac{dx}{(x^2+1)^2}$ has the value:

Linear Algebra

The determinant of the matrix $A = \begin{bmatrix} 2 & 1 & 1 \\ 2 & 3 & 2 \\ 1 & 2 & 1 \end{bmatrix}$ is

Probability and Statistics

Probability and Statistics: Mean, median, mode and standard deviation; random variables; Poisson, normal and binomial distributions; correlation and regression analysis. In a relay race there are five teams A, B, C, D, E. Assuming each team has an equal chance of any position (1st–5th), the probability that A, B, C finish 1st, 2nd, 3rd respectively is

Farm Machinery

The path traced by the material threshed between the cylinder and the concave of an axial flow thresher is

Farm Machinery

The farm machine/implement used only for preparing wetland is

Farm Machinery

The type of typical spray distribution profile of a hollow cone nozzle is

Sources of Power

Sources of Power: Sources of power on the farm — human, animal, mechanical, electrical, wind, solar and biomass; bio-fuels and their use in farm mechanization. The amount of biogas required to run a diesel engine is 0.65 m³ kW⁻¹h⁻¹. The minimum size of the Deenbandhu model biogas plant in m³ required to run a 1 kW (brake power) diesel engine daily for one hour is

Soil Mechanics

Soil Mechanics: Engineering properties of soils; fundamental definitions and relationships; index properties of soils; permeability and seepage analysis; shear strength, Soil compaction and Proctor test, Mohr's circle of stress, active and passive earth pressures; stability of slopes, Terzaghi's one dimensional soil consolidation theory. A soil sample has a porosity of 40%. Void ratio of the soil sample is

Hydrology

Hydrology: Hydrological cycle and measurement of its components; meteorological parameters and their measurement; analysis of precipitation data; runoff estimation; hydrograph analysis, unit hydrograph theory and application; stream flow measurement; flood routing, hydrological reservoir and channel routing, Infiltration – indices and equations, drought and its classification. In the Muskingum method of channel routing, Q2 = C0I2 + C1I1 + C2Q1. If K = 12 h, x = 0.15, Δt = 4 h, the coefficient C0 is

Surveying and Levelling

Match the contour characteristics in Column-I with the corresponding ground features in Column-II: | Column-I | Column-II | |---|---| | 1) Uniformly spaced contour lines | P) Flat ground | | 2) Widely spaced contour lines | Q) Steep ground | | 3) Closely spaced contour lines | R) Hill | | 4) Close contours, higher values inside | S) Uniform slope |

Soil-Water-Plant Relationship

Soil-Water-Plant Relationship: Water requirement of crops; consumptive use and evapotranspiration; measurement of infiltration, soil moisture and irrigation water infiltration. Tensiometer installed in the soil measures

Size Reduction and Material Handling

Size Reduction and Material Handling: Mechanics and energy requirement in size reduction of agriculture produce; particle size analysis for comminuted solids; size separation by screening; fluidization of granular solids-pneumatic, bucket, screw and belt conveying; cleaning and grading; effectiveness of separation; centrifugal separation of solids, liquids and gases; homogenization; filtration and membrane separation. Head pulley of a bucket elevator has an effective radius of 150 mm. In order to obtain the most satisfactory discharge from this elevator, the speed of the head pulley in rpm is

Processing of Agriculture Produce

Processing of Agriculture Produce: Processing of seeds, spices, fruits and vegetables; value addition of agriculture produce. The clean paddy production per annum is 160 million tonnes. Average milling quality analysis indicates husk content, total yield, and degree of polish as 22%, 73.32%, and 6% respectively. For average bran oil yield of 20%, the annual rice bran oil potential (million tonnes) is

Unit Operations in Dairy and Food Engineering

Preservation of Food: Kinetics of microbial death – pasteurization and sterilization of milk and other liquid foods; preservation of food by cooling and freezing; refrigeration and cold storage basics and applications. A batch of 10000 L milk is to be sterilized and packed in 20000 packets of 500 ml each. The mean Standard Plate Count (SPC) of Bacillus subtilis in 100 samples of fresh milk was found to be 50 ml⁻¹. The milk is to be sterilized such that each 500 ml packet is completely devoid of the organism. Minimum number of log cycle reduction for sterilization of this batch is

Heat and Mass Transfer

Heat and Mass Transfer: Steady state heat transfer in conduction, convection and radiation; transient heat transfer in simple geometry; working principles of heat exchangers; diffusive and convective mass transfer; simultaneous heat and mass transfer in agricultural processing operations; material and energy balances in food processing systems; water activity, sorption and desorption isotherms. A tube-in-tube counter-flow heat exchanger is heating oil from 35°C to 77°C by circulating hot water at 100°C. The outlet temperature of water is 70°C. The log-mean-temperature difference (LMTD) is

Numerical Methods

Using the trapezoidal rule, the value of the integral $I = \int_{4.0}^{5.2} \ln(x) \, dx$ (rounded to three decimal places) is ______ Given values: | $x$ | 4.0 | 4.2 | 4.4 | 4.6 | 4.8 | 5.0 | 5.2 | |---|---|---|---|---|---|---|---| | $y = \ln(x)$ | 1.386 | 1.435 | 1.482 | 1.526 | 1.569 | 1.609 | 1.648 |

Probability and Statistics

Probability and Statistics: Mean, median, mode and standard deviation; random variables; Poisson, normal and binomial distributions; correlation and regression analysis. Two cards are drawn at random without replacement from a pack of 52 playing cards. The probability that both cards are black (rounded to 3 decimals) is ______.

Farm Machinery

The total width between the two extreme furrow openers in a tractor-drawn 9-row wheat seed drill is 1.6 m. The average mass of wheat seeds dropped per meter of row length in each furrow opener is 2.15 g. Seed rate obtained with the seed drill in kg ha⁻¹ (rounded to 1 decimal) is ______.

Farm Machinery

The purchase price of a tractor is Rs. 5,50,000. Useful life is 10 years and salvage value is 10% of the purchase price. Following the sum-of-the-years-digits method, the depreciation in the 3rd year in Rs. is ______.

Machine Design

Machine Design: Design and selection of machine elements – gears, pulleys, chains and sprockets and belts; overload safety devices used in farm machinery; measurement of force, stress, torque, speed, displacement and acceleration on machine elements - shafts, couplings, keys, bearings and knuckle joints. A pair of straight teeth spur gears is transmitting power at 500 rpm. The pinion has 16 standard full-depth involute teeth of module 8 mm. The pitch line velocity of the pinion in m s⁻¹ (rounded to 2 decimals) is ______.

Hydrology

Hydrology: Hydrological cycle and measurement of its components; meteorological parameters and their measurement; analysis of precipitation data; runoff estimation; hydrograph analysis, unit hydrograph theory and application; stream flow measurement; flood routing, hydrological reservoir and channel routing, Infiltration – indices and equations, drought and its classification. A soil conservation structure has an expected life of 10 years and is designed for a flood magnitude of return period 50 years. The risk of this hydrologic design in percentage (rounded to 2 decimals) is ______.

Hydrology

Hydrology: Hydrological cycle and measurement of its components; meteorological parameters and their measurement; analysis of precipitation data; runoff estimation; hydrograph analysis, unit hydrograph theory and application; stream flow measurement; flood routing, hydrological reservoir and channel routing, Infiltration – indices and equations, drought and its classification. A watershed of area 80 ha has runoff coefficient 0.3. A storm of intensity 5 cm h⁻¹ occurs for a duration more than the time of concentration. The peak discharge in m³ s⁻¹ (rounded to 2 decimals) is ______.

Irrigation Water Conveyance and Application Methods

Irrigation Water Conveyance and Application Methods: Design of irrigation channels and underground pipelines; irrigation scheduling; surface, sprinkler and micro irrigation methods, design and evaluation of irrigation methods; irrigation efficiencies. A lateral has 12 sprinklers spaced 14 m apart in a sprinkler irrigation system. The laterals are spaced 20 m apart on the main line. If the recommended fertilizer dose is 80 kg/ha, the amount of fertilizer to be applied at each setting in kg (rounded to 2 decimals) is ______.

Processing of Agriculture Produce

Processing of Agriculture Produce: Processing of seeds, spices, fruits and vegetables; value addition of agriculture produce. In a rubber roll sheller, 250 mm diameter rolls are set at a clearance of 1 mm. If the mean thickness of paddy grains being shelled is 2 mm, the length of the husking zone (mm) (rounded to 2 decimals) is ______.

Evaporation and Drying

Evaporation and Drying: Concentration and drying of liquid foods – evaporators, tray, drum and spray dryers; osmotic dehydration and freeze drying; hydrothermal treatments; drying and milling of cereals, pulses and oilseeds; drying kinetics; psychrometry – properties of air-water vapor mixture. Air-water vapour mixture at 1 atmosphere pressure has 0.035 kg water vapour (kg dry air)⁻¹ and dry-bulb temperature of 37°C. Universal gas constant = 8.314 kJ (kg mole K)⁻¹. The humid volume (m³ (kg dry air)⁻¹) (rounded to 3 decimals) is ______.

Differential Equations

General solution to the differential equation y″ + 4y′ + 5y = 0 is

Vector Calculus

For vectors $\vec{F} = 3xy\,\hat{i} - y^2\,\hat{j}$ and $\vec{r} = x\,\hat{i} + y\,\hat{j}$, the value of line integral $\int_C \vec{F} \cdot d\vec{r}$ along the parabolic curve $C: y = 2x^2$ in the $xy$-plane from $(0,0)$ to $(1,2)$ is ______

Farm Power

A 3-cylinder 4-stroke CI engine coupled with a turbocharger has bore 120 mm and stroke 130 mm. Engine runs at 1600 rpm with volumetric efficiency 150%. Air-fuel ratio (weight basis) = 14.9:1, density of air entering the cylinder = 1.2 kg/m³. Fuel consumption in kg/h is

Farm Machinery

A level field of 1.2 ha (120 m × 100 m) is ploughed using a reversible mould board plough with total effective cutting width 0.64 m. Average field overlap is 80 mm between two consecutive laps. Average time taken for each turn is 30 seconds and mean operating speed is 5.0 km/h. The maximum effective field capacity in ha/h is

Farm Machinery

Thresher 'A': output 170 kg/h threshing paddy at 14% m.c., grain:straw = 45:55. Thresher 'B': output 160 kg/h at 13% m.c., grain:straw = 40:60. Both have threshing efficiency 97%. To thresh paddy at 12% m.c., grain:straw 40:60, in the least time, the selected thresher and its output in kg when operated for 5 hours will be

Sources of Power

Sources of Power: Sources of power on the farm — human, animal, mechanical, electrical, wind, solar and biomass; bio-fuels and their use in farm mechanization. A horizontal axis drag-type wind rotor fitted with 4 thin rectangular blades having drag coefficient 1.29 is used to extract power when average wind velocity in the rotor plane is 10 km/h. The maximum power coefficient is

Tractors and Power Tillers

Tractors and Power tillers: Type, selection, maintenance and repair of tractors and power tillers; tractor clutches and brakes; power transmission systems – gear trains, differential, final drives and power take-off; mechanics of tractor chassis; traction theory; three point hitches - free link and restrained link operations; steering and hydraulic control systems used in tractors; tractor tests and performance; human engineering and safety considerations in design of tractor and agricultural implements. A two-wheel drive tractor operating a plough at forward speed 5 km/h experiences wheel slip of 15%. If the angular speed of the rear axle is 2.4 rad/s, the rolling radius of the traction wheel in metres will be

Tractors and Power Tillers

Tractors and Power tillers: Type, selection, maintenance and repair of tractors and power tillers; tractor clutches and brakes; power transmission systems – gear trains, differential, final drives and power take-off; mechanics of tractor chassis; traction theory; three point hitches - free link and restrained link operations; steering and hydraulic control systems used in tractors; tractor tests and performance; human engineering and safety considerations in design of tractor and agricultural implements. The combined mass of a tractor seat and operator is 75 kg and the undamped natural frequency of the operator seat is 10 rad/s. If seat suspension damping rate is 600 N m⁻¹ s, the damping ratio is

Hydrology

Hydrology: Hydrological cycle and measurement of its components; meteorological parameters and their measurement; analysis of precipitation data; runoff estimation; hydrograph analysis, unit hydrograph theory and application; stream flow measurement; flood routing, hydrological reservoir and channel routing, Infiltration – indices and equations, drought and its classification. A catchment has 8 raingauge stations. Annual rainfall (cm): 93.8, 106.5, 170.6, 138.7, 87.8, 156.2, 180.9, 110.3. For a 10% error in estimating the mean rainfall, the optimum number of stations is

Soil and Water Erosion

Soil and Water Erosion: Mechanics of soil erosion - wind and water erosion: soil erosion types, factors affecting erosion; soil loss estimation; biological and engineering measures to control erosion; terraces and bunds; vegetative waterways; gully control structures, drop, drop inlet and chute spillways; earthen dams. On a 4% land slope in a medium rainfall zone, the horizontal spacing of bunds (m) and the length of bunds per hectare (m), respectively, are

Agricultural Drainage

Agricultural Drainage: Drainage coefficient; planning, design and layout of surface and sub- surface drainage systems; leaching requirement and salinity control; irrigation and drainage water quality and reuse; nonconventional drainage system. In a drainage area of 15 ha, the slope and drainage coefficient are 0.4% and 11 mm/day. Manning's roughness coefficient is 0.016. The inside diameter (mm) of the corrugated plastic tubing used for drainage is

Hydrology

Groundwater Hydrology: Groundwater occurrence; ground water movement; Darcy's Law, steady and unsteady flow in confined and unconfined aquifers, groundwater exploration techniques; overview of groundwater recharge estimation and artificial recharge techniques. A 20 cm diameter well fully penetrates a confined aquifer of thickness 20 m. After long pumping at 1500 L/min, steady drawdowns in wells at 30 m and 50 m are 2.0 m and 1.5 m respectively. Assuming π = 3.14, the transmissivity of the aquifer (m² s⁻¹) is

Fluid Mechanics

Fluid Mechanics: Ideal and real fluids, properties of fluids; hydrostatic pressure and its measurement; continuity equation, kinematics and dynamics of flow; Bernoulli's theorem; laminar and turbulent flow in pipes, Darcy- Weisbach and Hazen-Williams equations; flow through orifices, weirs and notches; flow in open channels, dimensional analysis – concepts of geometric dimensionless numbers. Water flows at velocity 1.6 m/s in a pipe of diameter 8 cm and length 100 m. With coefficient of friction f = 0.005 and g = 9.81 m/s², the head loss (m) due to friction in the pipe is

Size Reduction and Material Handling

Size Reduction and Material Handling: Mechanics and energy requirement in size reduction of agriculture produce; particle size analysis for comminuted solids; size separation by screening; fluidization of granular solids-pneumatic, bucket, screw and belt conveying; cleaning and grading; effectiveness of separation; centrifugal separation of solids, liquids and gases; homogenization; filtration and membrane separation. A cream separator has discharge radii of 6 cm and 9 cm and the density of cream and skim milk are 860 and 1035 kg/m³ respectively. The ideal radius (m) for placing the feed inlet is

Size Reduction and Material Handling

Size Reduction and Material Handling: Mechanics and energy requirement in size reduction of agriculture produce; particle size analysis for comminuted solids; size separation by screening; fluidization of granular solids-pneumatic, bucket, screw and belt conveying; cleaning and grading; effectiveness of separation; centrifugal separation of solids, liquids and gases; homogenization; filtration and membrane separation. Head rice contents in samples at feed inlet, head rice outlet, and broken rice outlet of an indented cylinder grader are 82%, 94%, and 15% respectively. If the grader receives feed at 1200 kg/h, the flow rate (kg/h) of head rice in the broken rice stream is

Evaporation and Drying

Evaporation and Drying: Concentration and drying of liquid foods – evaporators, tray, drum and spray dryers; osmotic dehydration and freeze drying; hydrothermal treatments; drying and milling of cereals, pulses and oilseeds; drying kinetics; psychrometry – properties of air-water vapor mixture. A batch of 100 kg grain at 32% moisture content (wet basis) is dried using hot air at 70°C and 30% RH. Henderson equation constants c and n for the grain are 8.5×10⁻⁶ and 2.07 respectively. Considering the maximum possible drying of the batch, the quantity of moisture removed (kg) is

Preservation of Food

Preservation of Food: Kinetics of microbial death – pasteurization and sterilization of milk and other liquid foods; preservation of food by cooling and freezing; refrigeration and cold storage basics and applications. A chiller working on mechanical vapour compression refrigeration (COP = 4.5) is used for cooling 12500 kg of fresh cow milk (cp = 3.8 kJ/kg·K) from 30°C to 4°C in 3 hours. Assuming ideal compression, the power consumed by the electric motor (kW) and the tonnage of refrigeration (TR), respectively, are

Evaporation and Drying

Two streams of air are adiabatically mixed as per the specifications given in the table below: | Stream | Flow rate (kg dry air/h) | Dry-bulb temp (°C) | Absolute humidity (g/kg dry air) | |---|---|---|---| | Fresh air | 727 | 35 | 27 | | Recycled air | 1020 | 55 | 40 | Using latent heat of vaporisation of water at 0°C = 2501 kJ/kg, $c_p$ (dry air) = 1.005 kJ/kg·K, $c_p$ (water vapour) = 1.880 kJ/kg·K, the dry-bulb temperature and absolute humidity of the mixed air (°C and g water vapour / kg dry air) are:

Vector Calculus

The directional derivative of $f(x,y,z) = xy^2 + yz^3$ at the point $(2,-1,1)$ in the direction of vector $\hat{i} + 2\hat{j} + 2\hat{k}$ is ______

Probability and Statistics

Probability and Statistics: Mean, median, mode and standard deviation; random variables; Poisson, normal and binomial distributions; correlation and regression analysis. The mean absolute deviation about the median for the data 3, 9, 5, 3, 12, 10, 18, 4, 7, 19, 21 (rounded to 2 decimals) is ______.

Farm Machinery

The application rate of an 18-nozzle hydraulic sprayer is 1120 L/ha. Nozzle spacing and forward speed are 400 mm and 3.4 km/h. Operating pressure is 2.1 MPa and pump efficiency is 60%. If 10% of the pump output power is used for agitating the liquid, the power needed to operate the sprayer in kW (rounded to 3 decimals) is ______.

Tractors and Power Tillers

Tractors and Power tillers: Type, selection, maintenance and repair of tractors and power tillers; tractor clutches and brakes; power transmission systems – gear trains, differential, final drives and power take-off; mechanics of tractor chassis; traction theory; three point hitches - free link and restrained link operations; steering and hydraulic control systems used in tractors; tractor tests and performance; human engineering and safety considerations in design of tractor and agricultural implements. A two-wheel drive tractor is taking a turn with radius of curvature 5.0 m. The minimum horizontal distance between the tipping axis and line of action of the CG is 800 mm. The angle between the line of action of centrifugal force and perpendicular direction to the tipping plane is 15°. If the vertical distance of the CG from ground level is 900 mm, the limiting speed (km/h) to prevent overturning (rounded to 2 decimals) is ______.

Tractors and Power Tillers

Tractors and Power tillers: Type, selection, maintenance and repair of tractors and power tillers; tractor clutches and brakes; power transmission systems – gear trains, differential, final drives and power take-off; mechanics of tractor chassis; traction theory; three point hitches - free link and restrained link operations; steering and hydraulic control systems used in tractors; tractor tests and performance; human engineering and safety considerations in design of tractor and agricultural implements. A two-wheel drive tractor with total weight 2000 kg has weight distribution 35% (front) and 65% (rear). Front tyres: width 0.18 m, diameter 0.56 m; rear: width 0.34 m, diameter 1.10 m. Tyre deflection is 20%; rolling resistance (kN) of the tractor in soil with average cone index 1000 kPa at wheel slip 15% (rounded to 2 decimals) will be ______.

Hydrology

Hydrology: Hydrological cycle and measurement of its components; meteorological parameters and their measurement; analysis of precipitation data; runoff estimation; hydrograph analysis, unit hydrograph theory and application; stream flow measurement; flood routing, hydrological reservoir and channel routing, Infiltration – indices and equations, drought and its classification. The peak of a flood hydrograph due to a 5-hour storm is 670 m³ s⁻¹. Total depth of rainfall is 9 cm. Assuming average infiltration loss of 0.2 cm h⁻¹ and constant baseflow of 30 m³ s⁻¹, the peak discharge of the 5-hour unit hydrograph for this catchment in m³ s⁻¹ is ______.

Soil and Water Erosion

Soil and Water Erosion: Mechanics of soil erosion - wind and water erosion: soil erosion types, factors affecting erosion; soil loss estimation; biological and engineering measures to control erosion; terraces and bunds; vegetative waterways; gully control structures, drop, drop inlet and chute spillways; earthen dams. A parabolic grassed water channel 8 m wide at the top and 60 cm deep is laid on a slope of 3%. Assuming Manning's 'n' = 0.04 m⁻¹ᐟ³s, the discharge capacity (m³ s⁻¹) of the channel (rounded to 2 decimals) is ______.

Soil-Water-Plant Relationship

Soil-Water-Plant Relationship: Water requirement of crops; consumptive use and evapotranspiration; measurement of infiltration, soil moisture and irrigation water infiltration. An undisturbed soil sample is collected when soil moisture is at field capacity. Core sampler inside diameter = 7.5 cm, height = 15 cm. Weight of core cylinder with moist soil = 2.81 kg, with oven-dry soil = 2.61 kg. Weight of the empty core cylinder = 1.56 kg. Assuming π = 3.14, the water depth (cm) per meter depth of soil (rounded to 2 decimals) is ______.

Irrigation Water Conveyance and Application Methods

Irrigation Water Conveyance and Application Methods: Design of irrigation channels and underground pipelines; irrigation scheduling; surface, sprinkler and micro irrigation methods, design and evaluation of irrigation methods; irrigation efficiencies. An irrigation stream of 27 L/s is diverted to a check basin of size 12 m × 12 m. Water holding capacity of the soil is 15% and average soil moisture content in the crop root zone before irrigation is 7.5%. Depth of crop root zone is 1.2 m, apparent specific gravity of soil is 1.5. Assuming no deep percolation loss, the irrigation time (minutes) required to replenish the root zone moisture to field capacity is ______.

Storage Systems

Storage Systems: Controlled and modified atmosphere storage; perishable food storage, godowns, bins and grain silos, packaging material and machines. Angle of internal friction of a certain grain (bulk density = 650 kg/m³) is 30°. A bin filled with this grain experiences a pressure of 60 kPa at its base. Ignoring the factor of safety, the safe height (m) to which water (density = 1000 kg/m³) can be filled in this bin (rounded to 2 decimals) is ______.

Heat and Mass Transfer

Heat and Mass Transfer: Steady state heat transfer in conduction, convection and radiation; transient heat transfer in simple geometry; working principles of heat exchangers; diffusive and convective mass transfer; simultaneous heat and mass transfer in agricultural processing operations; material and energy balances in food processing systems; water activity, sorption and desorption isotherms. The steady-state mass transfer coefficient (kg) based on water vapour pressure differential (VPD), operating across stagnant, non-diffusing air, was estimated to be 0.05 g mole s⁻¹ m⁻² kPa⁻¹. If VPD varies from 12 kPa to 7 kPa over a distance of 2 mm, the mass transfer coefficient (ky') based on equimolar counter-diffusion (g mole s⁻¹ m⁻² (mole fraction)⁻¹) (rounded to 1 decimal) is ______.

Preservation of Food

Preservation of Food: Kinetics of microbial death – pasteurization and sterilization of milk and other liquid foods; preservation of food by cooling and freezing; refrigeration and cold storage basics and applications. In an air blast freezing operation, a flat tray of 1.0 m×1.0 m×0.02 m is used to freeze filled depodded peas. Bulk density and moisture content of peas are 550 kg/m³ and 85% (w.b.) respectively. Latent heat of freezing from water to ice at -1°C is 335 kJ/kg and heat transfer occurs identically from the top and bottom surfaces of the tray. Convective film heat transfer coefficient on the heat transfer surfaces of the tray is 30 W/m²K and the thermal conductivity of frozen peas is 0.54 W/m·K. Assuming the tray to be a semi-infinite slab, the freezing time (minutes) to completely freeze the product (rounded to 1 decimal) is ______.