Assam ASSEB Higher Secondary Skill Subject Agri Engineering Technology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Drawbar power

Power available at the tractor drawbar for pulling implements. Calculated as draft (kN) multiplied by forward speed (m/s), giving kilowatts.

Wheel slip

Percentage loss of travel due to wheel spin. Computed as (no-load travel minus load travel) divided by no-load travel, multiplied by 100. Optimum is about 10–15%.

Three-point hitch

Tractor linkage with two lower arms and one top link that mounts and lifts implements. Categories I, II, and III differ in pin size and lift capacity.

Seed drill calibration

Procedure to set seed rate. Seed rate in kg/ha equals seed collected (kg) times 10,000 divided by effective width (m) times distance travelled (m).

Combine harvester losses

Grain lost at the header, during threshing, during separation, and during cleaning. Total loss should stay below about 2–3% of grain yield.

Moisture content wet basis

Water mass divided by total mass, multiplied by 100. Dry basis is water mass divided by dry matter mass, multiplied by 100. Convert using MCdb = MCwb/(100 − MCwb) × 100.

Equilibrium moisture content

Moisture content a grain reaches when it balances with the surrounding air's relative humidity and temperature. Grain is safe when its moisture equals the EMC.

Drying falling-rate period

Drying stage when the rate decreases because internal moisture diffusion limits water movement to the surface. Most grain drying occurs in this period.

Head rice yield

Proportion of whole milled kernels obtained from paddy. It is maximised when paddy is milled at about 14% moisture content.

Canning sterilisation

Heat process that destroys Clostridium botulinum spores in canned foods. It requires a specified time–temperature combination, unlike pasteurisation which destroys only vegetative cells.

Universal Soil Loss Equation

Model estimating water erosion: A = R × K × LS × C × P. A is soil loss in t/ha/yr; R is rainfall erosivity; K is soil erodibility; LS is slope; C is cover; P is practice.

Crop evapotranspiration

Water used by a crop through transpiration and soil evaporation. ETc = ET0 × Kc, where ET0 is reference evapotranspiration and Kc is the crop coefficient.

Duty of irrigation water

Area irrigated per unit supply. Duty (ha/cumec) = 8.64 × base period (days) / delta (m), where delta is the total depth of irrigation water.

Drip irrigation efficiency

About 90–95% of applied water is used by the crop. Drip delivers water near the root zone, reducing evaporation and deep percolation losses.

Contour bund

Earthen ridge built along a contour to intercept runoff and reduce soil erosion on sloping land. Spacing depends on slope and soil erodibility.

Farm building orientation

In hot climates, the long axis of a farm building should run east–west to reduce direct solar gain on side walls and improve comfort or storage conditions.

Livestock house ventilation

Controlled air exchange through ridge openings, side curtains, and fans. Minimum ventilation removes moisture and ammonia to keep animals healthy.

Hermetic grain storage

Sealed storage that limits oxygen, controlling insects and mould without chemicals. Suitable for durable grains kept at safe moisture content.

Concrete mix ratio 1:2:4

Cement, sand, and coarse aggregate proportion for general farm concrete work. Concrete must be cured for at least 7 days to gain strength.

Psychrometric properties

Dry-bulb temperature, wet-bulb temperature, relative humidity, and dew point describe air condition. They are used to design ventilation and drying systems.

Biogas from cattle dung

Anaerobic digestion produces gas containing about 55–65% methane. A family-size plant needs about 25 kg dung per day per cubic metre of gas.

Solar panel output

Power equals irradiance (W/m²) times panel area (m²) times efficiency. Output decreases as cell temperature rises above standard conditions.

Biomass gasification

Thermochemical conversion of rice husk, wood chips, or crop residue into producer gas containing carbon monoxide, hydrogen, and methane for engines or heat.

Wind power relation

Power in the wind is proportional to the cube of wind speed and to the rotor swept area. Wind pumps are used for low-lift water pumping.

Solar cabinet dryer

Drying system using a glazed collector and a drying chamber. Temperature must stay below the crop's heat-damage threshold to preserve quality.

RTK GPS accuracy

Real-time kinematic correction gives centimetre-level positioning for tractor guidance and precision field operations. Standard autonomous GPS gives metre-level accuracy.

Variable-rate application

Applying seed, fertiliser, or pesticide at rates that vary within a field according to prescription maps from soil tests, yield maps, or sensors.

NDVI

Normalised Difference Vegetation Index = (NIR − Red) / (NIR + Red). Higher values indicate denser, healthier vegetation and guide crop scouting.

Yield monitor

Sensor system on a combine that records grain flow and moisture with GPS position, producing yield maps that reveal within-field variability.

Tractor ROPS

Rollover protection structure with a seat belt that prevents death in tractor overturns. A tractor without ROPS must not be used on slopes.

PTO safety

Power take-off shaft must be guarded by a master shield. Loose clothing must not be worn near rotating shafts and guards must not be removed while running.

Break-even output

Output at which total revenue equals total cost. Calculated as fixed cost divided by (price per unit minus variable cost per unit).