Tamil Nadu PSC — Agricultural Engineering (Code 164, degree standard)

India · Tamil Nadu Public Service Commission · civil-service

693practice questions written to this syllabus
18subjects

Format

Degree-standard subject paper (for posts such as Assistant Engineer (Agri)).

Sections

Over the years

Units I–V were read; later units on farm power, machinery and processing were not fully captured.

Official source: https://tnpsc.gov.in/static_pdf/syllabus/dgagricultural-engineering.pdf

Subjects this exam draws on

Surveying & Levelling86 questionsSoil Science for Engineers31 questionsFluid Mechanics & Open Channel Hydraulics44 questionsSoil Mechanics26 questionsBuilding Materials, Theory of Structures & Construction41 questionsFarm Machinery & Equipment II — Plant Protection, Harvesting, Threshing17 questionsFarm Machinery Management & Economics13 questionsWatershed Hydrology37 questionsSoil & Water Conservation Engineering51 questionsWatershed Planning & Management41 questionsIrrigation Engineering (Soil-Water-Plant, Conveyance, Surface Methods)50 questionsSprinkler & Micro-Irrigation Systems35 questionsAgricultural Drainage Engineering29 questionsGroundwater, Wells & Pumps13 questionsRemote Sensing, GIS & GNSS for Land & Water92 questionsWater Resources Management, Floods & Canal Systems43 questionsStorage Engineering, Material Handling & Packaging9 questionsAgricultural Structures & Environmental Control35 questions

Five practice questions, worked

Original questions written to this exam's published syllabus and pattern. Not past papers.

1. How many links does a 20 m metric chain have, and what is the length of one link?

  1. 200 links of 0.1 m
  2. 150 links of 0.2 m
  3. 100 links of 0.3 m
  4. 100 links of 0.2 m
Answer and working

D. 100 links of 0.2 m

A 20 m metric chain has 100 links, so each link is 20/100 = 0.2 m. The 30 m chain has 150 links of 0.2 m, which is where 150 links comes from; Gunter's chain also has 100 links but is 66 ft long. 200 links of 0.1 m describes a tape graduated in decimetres, not a chain.

Surveying & Levelling · Chain and tape surveying, including tape corrections

2. In Jenny's equation of soil formation, which set lists the five soil-forming factors?

  1. Climate, vegetation, rainfall, temperature and slope gradient
  2. Texture, structure, porosity, organic matter and soil reaction
  3. Weathering, leaching, erosion, deposition and compaction
  4. Climate, organisms, relief, parent material and time
Answer and working

D. Climate, organisms, relief, parent material and time

Jenny (1941) wrote soil as a function of cl, o, r, p, t: climate, organisms, relief, parent material and time. Weathering, leaching and erosion are processes, not factors; texture and structure are soil properties that result from the factors.

Soil Science for Engineers · Soil formation and profile

3. What are the SI units of kinematic viscosity?

  1. N·s/m
  2. m²/s
  3. Pa·s
  4. m/s²
Answer and working

B. m²/s

Kinematic viscosity ν = μ/ρ = (Pa·s)/(kg/m³) = (kg/(m·s))/(kg/m³) = m²/s. Pa·s (N·s/m²) is the unit of dynamic viscosity, the commonest confusion.

Fluid Mechanics & Open Channel Hydraulics · Properties of fluids

4. A moist soil sample weighs 185 g and 160 g after oven-drying at 105–110 °C. What is its water content?

  1. 13.5%
  2. 86.5%
  3. 115.6%
  4. 15.6%
Answer and working

D. 15.6%

Water content is on the dry-mass basis: w = Mw/Ms = (185 − 160)/160 = 25/160 = 15.6%. Dividing by the moist mass (25/185 = 13.5%) is the commonest slip. 86.5% is dry mass over moist mass (160/185), and 115.6% is moist over dry (185/160).

Soil Mechanics · Phase relations

5. Why is a small amount of gypsum ground with Portland cement clinker?

  1. To accelerate hardening so that formwork can be struck within the first day
  2. To retard setting by controlling the fast reaction of tricalcium aluminate
  3. To lower the kiln temperature needed to form clinker from limestone and clay
  4. To raise the 28-day strength by forming extra calcium silicate hydrate gel
Answer and working

B. To retard setting by controlling the fast reaction of tricalcium aluminate

Without gypsum, tricalcium aluminate (C3A) reacts almost instantly with water and the paste flash sets. Gypsum is added after burning, at the grinding stage, so it has nothing to do with kiln temperature, and it is a retarder, not an accelerator or a strength-giving compound.

Building Materials, Theory of Structures & Construction · Bricks, stone and cement

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