ICAR AICE-JRF/SRF (PhD) — Agricultural Engineering subjects 38–43 · India · National Testing Agency for ICAR
Original practice questions written to the published syllabus · not past papersSprayers, weeders, mowers, reapers, combines and threshers: how they work, how to calibrate them and where losses come from.
In the exams: GATE AG Section 2 (sprayer problems in 6 of 8 papers 2019–26); ICAR AIEEA-PG Unit V; ICAR AICE subject 39 Unit 2; PRC ABE
ICAR AICE-JRF/SRF (PhD) — Farm Machinery and Power (subject 39, Unit 2)
Design of plant protection and harvesting equipment: droplet spectra and drift, electrostatic and air-assisted spraying, cutting mechanics, threshing and separation theory, loss functions and capacity.
How our questions for ICAR AICE-JRF/SRF spread across the units of Farm Machinery & Equipment II — Plant Protection, Harvesting, Threshing. Difficulty: 0 easy, 13 medium, 23 hard.
| Sprayers: hydraulic, air-assisted and electrostatic | 4 | |
| Nozzles and droplet spectra | 4 | |
| Mowers: reciprocating and rotary; mechanics of cutting | 4 | |
| Combine harvester: header, threshing cylinder and concave | 3 | |
| Combine separation and cleaning: straw walker and cleaning shoe | 3 | |
| Harvesting and threshing losses | 3 | |
| Cotton and sugarcane harvesting | 3 | |
| Sprayer calibration and application rate | 2 | |
| Weeders and inter-cultivation equipment | 2 | |
| Reapers | 2 | |
| Root-crop diggers | 2 | |
| Straw and residue management machines | 2 | |
| Threshers | 1 | |
| Chaff cutters | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
For any real nozzle spray, the number median diameter (NMD) compared with the volume median diameter (VMD) is
B. smaller
Small droplets dominate the count but carry little volume, while a few large droplets carry much of it, so NMD < VMD; VMD/NMD equals 1 only for a perfectly uniform spray.
A sprayer with a flow-based rate controller increases its speed by 40% on a smooth part of the field. To keep L/ha constant with the same conventional nozzles, nozzle pressure must rise by a factor of about
D. 2.0
Flow must rise by 1.4 times; since Q ∝ √P, pressure must rise by 1.4² = 1.96, about double. That also makes the spray finer, which is why conventional nozzles have a limited speed range under rate control. 1.2 takes the square root of 1.4 instead of squaring it; 2.8 doubles 1.4.
Which weeding tool is designed to remove weeds within the crop row between plants?
A. Finger weeder
Finger weeders have rubber fingers, driven by ground wheels, that reach into the row and flick out small weeds while bending round stronger crop stems. Sweeps work between rows; ridgers heap soil.
A weeder performance index combines field capacity, plant damage, weeding efficiency and power as
B. field capacity × (100 − plant damage) × weeding efficiency / power
The index rises with capacity, efficiency and the share of plants left undamaged, and falls with power input, so field capacity × (100 − plant damage) × weeding efficiency / power is the correct form. The others reward damage or penalise capacity.
Why is digging potatoes in wet, sticky clay particularly difficult for elevator diggers?
D. Wet clay does not sieve through the elevator and clings to tubers
Sticky soil forms a mass that will not fall through the rod gaps, so the elevator is overloaded and separation fails. Dry soil causes the opposite problem of clods.
The main environmental reason for developing in-situ rice straw management machines in north-west India was to
C. reduce air pollution from burning straw
Burning to clear fields for wheat causes severe seasonal air pollution; machines that manage straw without burning were developed and promoted for that reason.
Ten here, 36 in the app. The Laisha app has every practice question we have written to ICAR AICE-JRF/SRF in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
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