ASRB NET — Farm Machinery & Power / Land & Water Management Engineering / Agricultural Structures & Process Engineering · India · Agricultural Scientists Recruitment Board (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
ASRB NET — Farm Machinery & Power
PG-level recall and reasoning on plant protection and harvesting machinery, testing indices, residue management machinery and safety.
How our questions for ASRB NET spread across the units of Farm Machinery & Equipment II — Plant Protection, Harvesting, Threshing. Difficulty: 2 easy, 22 medium, 19 hard.
| Weeders and inter-cultivation equipment | 4 | |
| Mowers: reciprocating and rotary; mechanics of cutting | 4 | |
| Combine harvester: header, threshing cylinder and concave | 4 | |
| Combine separation and cleaning: straw walker and cleaning shoe | 4 | |
| Harvesting and threshing losses | 4 | |
| Sprayers: hydraulic, air-assisted and electrostatic | 3 | |
| Nozzles and droplet spectra | 3 | |
| Dusters | 3 | |
| Threshers | 3 | |
| Straw and residue management machines | 3 | |
| Reapers | 2 | |
| Root-crop diggers | 2 | |
| Cotton and sugarcane harvesting | 2 | |
| Sprayer calibration and application rate | 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.
A common practical rule for replacing a set of spray nozzles is when their measured flow exceeds that of new nozzles by about
C. 10 per cent
Worn orifices enlarge; once flow is roughly 10% above new the pattern is also distorted and overdosing is significant. 1% is within measurement error; waiting for 50% would badly overdose.
A granule applicator is calibrated using dry sand instead of the actual granular product. The main problem is that
C. output depends on particle size, density and flowability, so sand output does not predict product output
Metering devices deliver a volume that depends on how the particles flow; mass per unit volume differs by material, so calibration must use the product itself. The idea that granules are always metered by volume, so any free-flowing material gives the same kg/ha, is the misconception the question targets.
The cono weeder used in rice has
A. two conical rotors with serrated strips in tandem and a float
The cono weeder has two cones set in tandem with opposite orientation, serrated strips that churn soil, and a float that stops it sinking in puddled soil. It is pushed and pulled between rows.
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.
Registration of a reciprocating cutter bar is correct when
B. at each stroke end the knife section centre lines coincide with the guard centre lines
That is the definition of registration. Straight guard points and parallel knife motion are alignment, a separate adjustment. Poor registration gives uneven cutting and uncut stems.
Machine loss (threshing, separating and cleaning) of a combine is obtained from field counts as
A. total loss behind the machine minus header and pre-harvest losses
Grain found behind the machine includes what was already on the ground and what the header dropped; subtracting both leaves the loss from the threshing, separating and cleaning units.
A multi-crop axial-flow thresher differs from a conventional throw-in thresher in that
D. the crop moves helically along the drum axis, threshing and separating over a long path
Axial movement gives longer residence and separation; different crops are handled by changing speed, concave and sieves.
To reduce bruising on a potato digger elevator, the operator should
C. keep the elevator loaded with soil as a cushion and match its speed to forward speed
A soil cushion protects tubers; a bare fast-running elevator and high drops cause bruising. Heavy agitation also damages tubers.
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.
Compared with spindle pickers, stripper cotton harvesters
D. harvest all bolls with more burs and trash, needing extra cleaning
Strippers take everything, so field cleaners or burr extractors and more gin cleaning are needed. They suit short, compact plants.
Ten here, 43 in the app. The Laisha app has every practice question we have written to ASRB NET 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.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
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