BCS Agriculture cadre — Agricultural Engineering (subject code 821) · Bangladesh · Bangladesh Public Service Commission
Original practice questions written to the published syllabus · not past papersBCS Agriculture cadre — Agricultural Engineering (subject code 821) is a government recruitment exam run by Bangladesh Public Service Commission, for candidates in Bangladesh. Preliminary 200-mark MCQ (2 h); written 900 marks; viva 200 marks. Code 821 is a 200-mark post-related paper.
Source: bpsc.gov.bd.
Checked against the exam body's published information. Formats and fees change; confirm the current edition there before you book.
Keeping fruits and vegetables alive and saleable after harvest: cooling, handling, packhouses, controlled atmospheres and processing.
Our 27 BCS Agriculture cadre questions in this subject: 14 easy, 9 medium, 4 hard, across 10 units.
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
These 10 were written to BCS Agriculture cadre and are not shown on any other exam's page.
Pitting, water soaking and failure to ripen in banana or mango held at 5 degC are symptoms of
C. chilling injury
Chilling injury occurs in tropical and subtropical produce at temperatures above freezing but below a crop-specific threshold. Freezing injury needs temperatures below the tissue freezing point, well below 5 degC.
A hydrocooler handles 5 t/h of sweet corn (specific heat 3.9 kJ/kg K) cooled from 25 degC to 5 degC. If the chilled water may warm by only 2 K as it passes through the bed (water specific heat 4.18 kJ/kg K), the water circulation rate needed for the product load alone is about
D. 13.0 kg/s
Product load = (5 000/3 600) x 3.9 x 20 = 108.3 kW. Water flow = 108.3 / (4.18 x 2) = 13.0 kg/s. Using a 20 K rise (the product's temperature drop) instead of 2 K gives a tenth of the flow; 25.9 kg/s forgets the 2 K rise. 1.30 kg/s uses the 20 K product drop as the water rise; 46.7 kg/s multiplies the correct flow by 3.6.
A wash tank holds 100 L of water. How much sodium hypochlorite solution containing 5% available chlorine (50 g/L) must be added to give 150 mg/L free chlorine, assuming no chlorine demand from the water?
D. 300 mL
Chlorine needed = 100 L x 150 mg/L = 15 000 mg = 15 g. Volume of 50 g/L stock = 15/50 = 0.3 L = 300 mL. 3 000 mL and 30 mL are decimal slips; 3 000 mL also results from treating 5% as 5 g/L. In practice organic matter consumes chlorine, so the level is monitored and topped up.
Curing of onion bulbs before storage is primarily intended to
C. dry the neck and outer scales into protective skins
Onion curing dries the neck and outer scales, which seals the bulb against water loss and decay organisms. Sprouting is to be avoided in storage.
Recommended storage temperatures for fresh commodities are best treated as
B. ranges that vary by cultivar, maturity and source
Handbooks give ranges, and they differ between cultivars, maturities, regions and references. Chilling-sensitive crops need warmer storage than temperate crops.
The dehydration method that gives the best retention of shape, colour and aroma and the best rehydration is
C. freeze drying
Freeze drying sublimes ice from frozen product at low temperature, preserving structure and volatiles; it is also the most expensive method.
Juice flows at 5 000 kg/h (specific heat 3.8 kJ/kg K) through a pasteuriser heated from 10 degC to 90 degC with no heat regeneration. The heating duty is about
A. 422 kW
Q = (5 000/3 600) x 3.8 x 80 = 422 kW. Forgetting to convert per hour to per second gives 1520 (in MJ/h, not kW). A regenerative section would recover much of this heat. 475 kW uses the 90 degC outlet temperature as the rise; 117 kW divides by 3.6 a second time.
Jelly differs from jam in that jelly is made from
A. clarified fruit juice
Jelly is a clear gel from strained juice; jam uses pulp; marmalade is citrus-based with suspended peel.
The pH that separates low-acid from high-acid canned foods, determining whether a pressure (retort) process is required, is
B. 4.6
Clostridium botulinum does not grow at pH 4.6 or below; low-acid foods above it need a pressure process. 7.0 is neutrality; 3.0 and 5.6 have no regulatory meaning for this purpose.
Chilli growers are advised to dry harvested pods quickly on clean surfaces rather than heaping them on the ground mainly to
C. prevent mould growth and aflatoxin contamination
Slow drying of moist heaped pods favours moulds such as Aspergillus that produce aflatoxins. Quick drying on clean surfaces or in dryers limits this.
This plan follows where our questions actually fall, so the time goes where the marks are likely to be. It is our reading of the syllabus, not the exam body's weighting.
Read the manual chapters for these first and do every worked question you can find on them.
Aim for one sitting per unit, then mixed questions across them.
Learn the definitions, classifications and standard numbers; these units are more often recalled than worked.
Come back to these after a first pass, untimed, and read every explanation, including for the options you rejected.
Do these early in revision so they are fast on the day.
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