II Grade Overseer / Draftsman (Civil) — PWD / Irrigation / LSGD — 2021 — Official Paper — Kerala PSC PYQ Practice with Answers

Correct answer (Option A):\n\nFormula:\nTime Factor = (Number of days the canal has actually run) / (Total number of days of the irrigation period)\n\nThis dimensionless factor is highly useful in irrigation engineering for scheduling water distribution and calculating the actual efficiency of a canal layout during a crop season.\n\nWhy others are wrong:\nOption B (Capacity factor) is the ratio of mean supply discharge to the design capacity of the canal. Options C and D refer to discharge points or volumetric properties rather than time periods.\n\nStudy tip:\nAlways remember that time factor links actual running days to total available period days, whereas capacity factor links mean discharge to peak capacity.

Correct answer (Option B):\n\nCompressibility is the measure of the relative volume change of a fluid as a response to a pressure change. For a given mass of fluid, an increase in pressure leads to a decrease in its volume, which directly describes the compressibility property.\n\nWhy others are wrong:\nOption A describes resistance to gradual deformation by shear stress. Option C describes fluid movement in narrow spaces due to adhesion/cohesion. Option D describes the elastic tendency of a fluid surface which makes it acquire the least surface area.\n\nStudy tip:\nBulk modulus is the reciprocal of compressibility. A higher bulk modulus means the liquid is less compressible.

Correct answer (Option D):\n\nTo compile a complete and accurate detailed engineering estimate, three primary components are mandatory:\n1. Drawings: To compute the exact quantities of various items of work.\n2. Specifications: To understand the quality of materials and workmanship.\n3. Rates: From the Schedule of Rates to compute the cost of quantities.\nOption D is correct.\n\nWhy others are wrong:\nOptions A, B, and C are each single necessary elements, but none of them are sufficient on their own to create an entire workable project estimate.\n\nRemember:\nAn estimate represents the probable cost of a project before construction begins and cannot be finalized without full execution parameters.

Correct answer (Option A):\n\nLinseed oil acts as the primary vehicle or drying oil medium in standard oil paints. It holds the pigment particles in suspension and forms a tough, adhesive, and protective thin film upon oxidizing and drying.\n\nWhy others are wrong:\nOption B is an organic solvent not used in regular oil painting vehicles. Options C and D represent thinners or volatile solvents used primarily to adjust viscosity and speed up drying times rather than acting as the basic carrier fluid.\n\nStudy tip:\nDouble-boiled linseed oil is commonly preferred in civil engineering works to ensure uniform drying properties on timber or steel.

Correct answer (Option D):\n\nThe wilting co-efficient (or permanent wilting point) is the soil moisture percentage at which the water tension matches the maximum osmotic extraction capacity of plant roots. Beyond this limit, plants permanently droop and dry up.\n\nWhy others are wrong:\nOption A is the moisture range between field capacity and wilting point. Option B is the fraction easily drawn by plants. Option C is the maximum water retained against gravity.\n\nStudy tip:\nPlants exert an extraction suction pressure of roughly 15 atmospheres at the permanent wilting point.