List of top Questions asked in GATE Agricultural Engineering

A falling ball viscometer is used to determine the dynamic viscosity of sunflower oil. The viscometer has a tube length of 10 cm with the ball diameter of 0.68 mm. The densities of oil and the ball are 921 kg m$^{-3$ and 2420 kg m$^{-3}$, respectively. If the ball takes 44.5 s to fall from top of the tube, the viscosity of the oil in Pa s is _____.} \textit{[Round off to three decimal places]}

A cylindrical metallic silo of 3 m internal diameter and 10 m depth is loaded with maize grain having bulk density of 720 kg m$^{-3}$. The angle of internal friction between the maize grains is 24°, and that between the grain and wall is 22°. Using Airy’s theory, the calculated lateral pressure in kPa at the bottom of the silo is _____. \textit{[Round off to two decimal places.]}

Parboiled paddy is to be dried in a tray dryer under steady state conditions from an initial free moisture content of 0.40 kg H$_2$O (kg dry solid)$^{-1}$ to final free moisture content of 0.02 kg H$_2$O (kg dry solid)$^{-1}$. The dry solid mass is 99.8 kg and the top surface area for drying is 4.654 m$^2$. The drying is occurring in both constant and falling rate periods. If constant drying rate of 1.51 kg H$_2$O m$^{-2}$ h$^{-1}$ is followed up to a critical moisture content of 0.195 kg H$_2$O (kg dry solid)$^{-1}$, then the total drying time in hour will be _____. \textit{[Round off to two decimal places.]}

Sweet sorghum with an initial average particle size of 4.0 mm was pulverized using a burr mill at two different gap settings between stones. The average feed rate of the material is 200 kg h$^{-1$. The resultant flour was analyzed by IS sieves for particle size determination and was found to be 0.336 mm and 0.306 mm for the first and second gap settings, respectively. Using Kick’s law, if the power required to grind the sorghum at first setting is 7.2 kW, the power requirement in kW with the second setting is _____.} \textit{[Round off to two decimal places]}

A walk-in deep freezer wall is made of 120 mm thick brick layer on the outside followed by 75 mm thick concrete and 50 mm thick cork layers inside. The mean temperatures measured over inside and outside wall surfaces are -18°C and 24°C, respectively. The thermal conductivity of brick, concrete and cork are 0.69, 0.76 and 0.043 W m$^{-1$ K$^{-1}$, respectively. Considering one square meter wall surface area, the heat transfer rate in W is _____.} \textit{[Round off to one decimal place]}

The static weight on front and rear axles of a two-wheel drive tractor are 3 kN and 9 kN, respectively. The wheel-base of the tractor is 2.1 m and the tractor pulls a load of 7.5 kN. The perpendicular distance from the front wheel ground contact point to the line of pull is 680 mm. Neglecting the wheel contact off-set on the ground, the weight transfer onto the rear axle in kN is _____. \textit{[Round off to two decimal places]}

The crank radius and connecting rod length of an IC engine are 250 mm and 1000 mm, respectively. If the crank turns 100° from the head dead centre and the net force acting on the piston along its direction of motion is 35 kN, the turning moment of the crank shaft at that instant in kN m is _____. \textit{[Round off to two decimal places]}

A tractor operated 12 $\times$ 60 cm boom sprayer had an overlap of 30 cm between the successive passes during field operation at an average speed of 4.2 km h$^{-1}$. A total time loss of 7.5 min ha$^{-1}$ was observed during turnings. Assuming no overlap of spray material between adjacent nozzles, the field efficiency of the sprayer in per cent is _____. \textit{[Round off to two decimal places.]}

A mild steel flange-mounted single shear pin (Ultimate shear strength = 42 MPa) is used in a flange. The perpendicular distance between the axis of driving shaft and the shear pin axis is 100 mm. If the speed of the driving shaft is 300 rpm, the maximum power the shaft could transmit in kW before the failure of the pin is _____. \textit{[Round off to two decimal places.]}

In a subsurface drainage network, 12 lateral drains each of 100 m long are laid at a spacing of 50 m. These lateral drains are connected to a collector drain. When the water table dropped 50 cm below the soil surface in 4 days, the average discharge at the outlet of the collector drain was found to be 12 L s$^{-1$. The average drainable porosity of soil in per cent is _____.} \textit{[Round off to two decimal places]}

A watershed with various land uses (as specified in the table below) receives a rainfall of 152.4 mm. If an initial abstraction (I$_a$) is 0.2 times the potential maximum retention (S), and the antecedent moisture content (AMC) of averaged condition is assumed, the depth of runoff volume in mm is _____. \textit{[Round off to two decimal places]}

The mass fraction retained on the $i$-th sieve is $x_i$ and $D_{pl}$ is the average opening size of $i$-th and $(i-1)$-th sieves. The volume surface mean diameter ($D_s$) of particles retained on $n$ number of sieves is __________.

Match the following reactants in Column I with the most appropriate purpose used in processing as mentioned in Column II

A 5 × 20 cm seed drill has a ground drive wheel of rolling diameter 0.5 m. While testing under laboratory condition, 320 g of seeds were collected in 20 revolutions of the ground drive wheel. The same seed drill when operated in a 2 ha field, amount of seeds dropped was found to be 185 kg. The variation in the seed dropped between laboratory and field conditions due to skid of ground drive wheel is __________ (Take $ \pi = 3.14 $)

A 3.6 m combine harvester was tested over a crop strip of 20 m length and the following data were obtained while testing: Total material left over walker = 8.5 kg
Free seed over walker = 100 g
Unthreshed seed over walker = 50 g
Total material left over shoe = 5.5 kg
Free seed over shoe = 250 g
Unthreshed seed over shoe = 80 g
Total seed collected in the grain tank = 16.5 kg The grain yield (tonne ha$^{-1}$) and cylinder loss (%) are:

An ideal gas is compressed adiabatically (Adiabatic exponent $ \gamma = 1.4 $) from 98 kPa to 480 kPa and the specific volume of the gas at the beginning of the compression stroke is $ 0.45 \, \text{m}^3 \, \text{kg}^{-1} $. The specific work done on the gas in kJ kg$^{-1}$ is __________.

A sample of 90% saturated clay soil has void ratio and specific gravity of 0.8 and 2.7, respectively. The bulk unit weight of soil in N m$^{-3}$ is __________.

A parabolic shaped grass-waterway is to be designed to carry a flow of 2.85 m³/s down the slope of 3%. The permissible velocity of water in the waterway is 1.78 m/s. If the freeboard depth is excluded, the most appropriate top width in m and depth in m, respectively are (Take Manning’s roughness coefficient = 0.04).

The pressure drop through a well-designed constriction is to be used for measuring the velocity of flow through a circular pipe. If the pressure drop from a 0.1 m diameter section to a 0.05 m diameter section of the pipe is 7.5 kPa, the velocity in m/s in the 0.1 m diameter section of the pipe is __________. (Take density of liquid = 1000 kg/m³)

The water activity of potato is 0.942. As per Raoult’s law, the most efficient solution for osmotic dehydration of potato is__________.
(Molar mass of sucrose = 342 g mole$^{-1}$, and NaCl = 58.5 g mole$^{-1}$)

The ratio of soil loss from the field plot length to that from the unit plot with a slope length of 22.13 m is 0.5. If the slope length from the watershed divide is 600 m and the slope gradient is 8%, the topographic factor in the Universal Soil Loss Equation is _____. \textit{[Round off to two decimal places]}

The area of a rectangular field was measured using a 30 m survey chain, which was later found to be 5 cm short. If the length and width of the field measured using this chain were 542 m and 554 m, respectively, the true area of the field in ha is _____. \textit{[Round off to two decimal places]}

A milk sample contains $4 \times 10^5$ spores of $C. botulinum$ (D value of 1.2 min at 121.1 °C) and $7 \times 10^6$ spores of $L. monocytogenes$ (D value of 0.9 min at 121.1 °C) per mL. If the milk is heated at a uniform temperature of 121.1 °C to obtain a probability of spoilage of 1 in 1000 cans, the minimum heating duration in minutes is _____. \textit{[Round off to two decimal places.]}

The function $ (x - 2)^2 (x + 2)^2 $ has

A two-wheel drive tractor is fitted with driving wheels having rolling radius of 860 mm. The effective gear ratio between the engine to the drive wheels is 98:1 and the power transmission efficiency at that gear ratio is 86%. If the engine torque is 520 N m, the ground thrust developed by the drive wheels in kN is _____.