UPHESC Assistant Professor Agricultural Engineering PYQs

Concept: A metric chain of 30 m has 150 links; a 20 m chain has 100 links.

1. Length of one link = 30 m ÷ 150 = 0.20 m = 20 cm.
2. Both 20 m and 30 m metric chains have 20 cm links.

Short trick: Metric chain link = 20 cm always.

Concept: In plane surveying the earth is treated as flat; this is acceptable up to about 250 km².

1. Over 250 km² (large areas), curvature matters → geodetic surveying.
2. The arc–chord difference for 18.2 km is only about 1 cm.

Short trick: Plane survey ≤ 250 km²; beyond → geodetic.

Concept: Contour interval is chosen according to the nature of ground. Smaller intervals are used for flatter land.

1. Flat / almost level ground: about 0.2–0.5 m.
2. Rolling or undulating ground: about 0.5–2 m.
3. Hilly or steep ground: 1–3 m or more.

Short trick: Small interval (≤ 0.5 m) → nearly level land.

Concept: True length = (incorrect chain length ÷ true chain length) × measured length, i.e. $L_t=\frac{L^{\prime }}{L}\times l$.

1. L' = 20.03 m, L = 20 m, l = 327 m.
2. $L_t=\frac{20.03}{20}\times 327=327.49$ m.

Short trick: Too-long chain → measured is less → add the correction.

Concept: Included angle at B is the angle between the lines BA and BC.

1. Back bearing of AB (bearing of BA) = 120° + 180° = 300°.
2. Bearing of BC = 78°. The difference is 300° − 78° = 222°.
3. Interior angle = 360° − 222° = 138°. The deflection is 180° − 138° = 42°.

Short trick: Included angle = 180° − (difference of fore bearings) = 180° − 42° = 138°.

Concept: An alidade is the sighting rule used on a plane table to draw rays towards objects.

1. Plain alidade or telescopic alidade.
2. Other plane-table accessories: trough compass, spirit level, U-fork with plumb bob.

Short trick: Plane table = alidade + U-fork + trough compass.

Concept: Magnetic meridian is the direction shown by a freely suspended, balanced magnetic needle that local attraction does not disturb.

1. True meridian runs towards the geographic poles and is fixed by astronomical observation.
2. Grid meridian is a reference line on a map grid. 'True magnetic' and 'prismatic' meridians are not standard terms.

Short trick: Free needle → magnetic meridian; sun or stars → true meridian.

Concept: Deep-litter housing needs about 0.3–0.4 m² (≈3–4.5 ft²) of floor per adult hen.

1. For 100 adult hens this gives about 30–42 m².
2. Smaller areas (7–17, 17–27 m² per 100) suit chicks and growers.

Short trick: Adult hen ≈ 0.3–0.4 m² → ×100 = 30–42 m².

Concept: A storage tank must hold the shortfall that builds up when demand exceeds supply.

1. Peak deficit = (80,000 − 32,000) × 3 = 1,44,000 L.
2. In the rest of the period demand (35,000 lph) is also more than supply (32,000 lph), so the tank can never refill. With the data as printed, no balancing tank size exists.
3. None of 56,000, 24,000, 28,000 or 94,000 L follows from the given figures, so no option can be marked correct.

Short trick: Tank size = cumulative (demand − supply) during peak, and supply must exceed demand in the off-peak period to refill it.

Concept: A larger greenhouse has a smaller cover (surface) area per unit floor area, and natural ventilation works less well across a wider house.

1. Heat loss through the cover per m² of floor goes down.
2. Air exchange from side or roof vents reaches the centre less well.
3. So the air and plant temperature inside rises.

Short trick: Bigger house → less surface per floor area and poorer ventilation → warmer plants.

Concept: Heat moves in a greenhouse by all three modes.

1. Radiation: solar gain in, long-wave loss out.
2. Conduction: through the glazing and the soil.
3. Convection: air movement, ventilation and infiltration.

Short trick: R + C + C – all three.

Concept: A lean mix of 1 : 4 : 8 (cement : sand : coarse aggregate) is the usual bed concrete under the foundation of farm buildings.

1. 1 : 2 : 4 (M15) is used for RCC work such as lintels and slabs.
2. 1 : 3 : 6 is used for floors and PCC work; 1 : 4 : 8 is the leanest and goes under foundations.

Short trick: Foundation bed = leanest mix 1 : 4 : 8.

Concept: Width of a strip foundation is B = load per metre run ÷ safe bearing capacity of soil.

1. B = 450 kg/m ÷ 5000 kg/m² = 0.09 m.
2. 0.09 m (9 cm) is not among the options. 0.90 m would need a load of 4500 kg/m.
3. As printed, no option is correct.

Short trick: B = W/q → check the units and the order of magnitude.

Concept: Macadam road construction was developed by John Loudon McAdam (1756–1836), a Scottish engineer.

1. It uses layers of compacted broken stone; with tar binder it becomes tar-macadam (tarmac).
2. Trésaguet (a French engineer) and Telford (also Scottish) gave other methods.

Short trick: Mc = Scottish name → McAdam the Scot.

Concept: A gully passes through four stages (Ireland et al.).

1. Formation – channel erosion and down-cutting of the topsoil.
2. Development – upstream movement of the gully head and widening.
3. Healing – vegetation begins to grow in the channel ('heating stage' in the question means this healing stage).
4. Stabilisation – bed and banks reach stable slope; no further erosion.

Short trick: F-D-H-S: Form, Develop, Heal, Stabilise.

Concept: Earth from each borrow pit forms a length of bund. The pit length plus the berm (gap between pits) equals that bund length.

1. Bund length per pit = pit earthwork ÷ bund section = 6.00 ÷ 1.55 = 3.87 m.
2. Berm = 3.87 − 3.50 = 0.37 m.

Short trick: Berm = (pit quantity ÷ bund section) − pit length.

Concept: Runoff coefficient C = runoff ÷ rainfall. In practice it ranges from about 0.1 (sandy, wooded land) to about 0.8 and above (paved or rocky surfaces).

1. Cultivated lands: about 0.3–0.6.
2. Impervious or rocky catchments: about 0.7–0.9.
3. Of the options given, the largest practical value is about 0.80.

Short trick: Concrete or rock ≈ 0.8 → top of the usual range.

Concept: Woodruff–Zingg formula: $d=17H\left(\frac{V_m}{V}\right)\cos \theta$.

1. H = 18 m, V_m = 18 kmph (threshold), V = 14 kmph, θ = 22°.
2. $d=17\times 18\times \frac{18}{14}\times \cos {22}^{\circ }=306\times 1.2857\times 0.9272$.
3. d ≈ 364.78 m.

Short trick: Protection ≈ 17 H, adjusted by velocity ratio and cos θ.

Concept: Rhizosphere (Greek rhiza = root) is the soil zone occupied and influenced by plant roots.

1. It is the zone of intense microbial activity and water and nutrient uptake.
2. Hydrosphere is all the water on Earth; 'hygrosphere' and 'capillary sphere' are not terms for the root zone.

Short trick: Rhizo = root.

Concept: USLE (A = R·K·LS·C·P) was developed by Wischmeier and Smith of the USDA (1965, revised 1978).

1. It is based on more than 10,000 plot-years of runoff data from the USA.
2. Revised as RUSLE in the 1990s.

Short trick: USLE → USDA → USA.