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ICAR AICE-JRF/SRF Farm Power Sources: practice questions

ICAR AICE-JRF/SRF (PhD) — Agricultural Engineering subjects 38–43 · India · National Testing Agency for ICAR

Original practice questions written to the published syllabus · not past papers
10worked here, free
25written to this exam in this subject
7syllabus units

About ICAR AICE-JRF/SRF

ICAR AICE-JRF/SRF (PhD) — Agricultural Engineering subjects 38–43 is a PhD, fellowship and lectureship exam run by National Testing Agency for ICAR, for candidates in India. LAN-based computer test, 2 hours, 120 MCQs: 20 Part A (general knowledge and reasoning), 50 Part B (core group), 50 Part C (specialisation); four options.

Source: icar.org.in.

Checked against the exam body's published information. Formats and fees change; confirm the current edition there before you book.

Farm Power Sources in ICAR AICE-JRF/SRF

Energy in agriculture at PG depth: energy audit coefficients and indices, mechanisation indices, farm power availability trends, and renewable energy conversion efficiencies.

Where the energy for farm work comes from, how much is available, and how mechanisation is measured.

Our 25 ICAR AICE-JRF/SRF questions in this subject: 5 easy, 13 medium, 7 hard, across 7 units.

10 practice questions, worked

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 ICAR AICE-JRF/SRF and are not shown on any other exam's page.

Question 1 · hard

A worker consumes oxygen at 1.5 L/min while working. Taking an energy equivalent of 20.1 kJ per litre of oxygen and a gross mechanical efficiency of 20%, estimate the mechanical power output.

  1. 502.5 W
  2. 100.5 W
  3. 1.68 W
  4. 2,512.5 W
Answer and working

B. 100.5 W

Metabolic power = 1.5 × 20.1 = 30.15 kJ/min = 30,150/60 = 502.5 W. Mechanical output = 0.20 × 502.5 = 100.5 W. 502.5 W is the metabolic rate before applying efficiency; dividing by 3600 treats the rate as per hour; dividing by the efficiency instead of multiplying gives 2,512.5 W.

Question 2 · medium

A wind turbine rotor of 20 m radius turns at 30 rpm in a 10 m/s wind. What is its tip speed ratio?

  1. 60
  2. 0.628
  3. 6.28
  4. 3.14
Answer and working

C. 6.28

ω = 2π × 30/60 = 3.1416 rad/s; tip speed = ω R = 62.8 m/s; λ = 62.8/10 = 6.28. Using rpm directly gives 60; 0.628 is a decimal slip; 3.14 treats the 20 m radius as a diameter.

Question 3 · medium

A 250 kW wind turbine on a farm produces 547.5 MWh in a year. What is its capacity factor?

  1. 219%
  2. 25.0%
  3. 2.5%
  4. 75.0%
Answer and working

B. 25.0%

Capacity factor = 547,500 kWh / (250 kW × 8760 h) = 0.250 = 25.0%. Dividing MWh by kW without converting gives 219% (impossible, above 100%); 75.0% assumes only 8 operating hours a day, but capacity factor is referred to all 8760 hours. 2.5% is a factor-of-ten slip.

Question 4 · hard

At a site the wind blows at 4 m/s for half the time and 8 m/s for the other half. What is the ratio of the true mean wind power to the power calculated from the mean wind speed?

  1. 1.33
  2. 1.00
  3. 0.75
  4. 2.00
Answer and working

A. 1.33

Mean of V³ = (64 + 512)/2 = 288; (mean V)³ = 6³ = 216; ratio = 288/216 = 1.33. Because power depends on V³, using the mean speed underestimates energy; this is why wind speed distributions (Weibull, Rayleigh) are used. 1.00 assumes power is linear in speed; 0.75 is the inverse ratio, 216/288.

Question 5 · easy

'Agrivoltaics' refers to:

  1. Using crop residues to manufacture PV cells
  2. Running tractors on stored PV electricity only
  3. Using the same land for crops or grazing and for PV electricity generation
  4. Drying harvested crops in bins with electric heaters powered by diesel generators
Answer and working

C. Using the same land for crops or grazing and for PV electricity generation

Agrivoltaic systems raise or space PV arrays so that crops can grow or animals graze beneath them, sharing land between food and power.

Question 6 · hard

Which statement comparing biodiesel with petroleum diesel is correct?

  1. Biodiesel has a higher heating value and better cold-flow properties than petroleum diesel
  2. Biodiesel has a lower flash point than petroleum diesel, making it more hazardous to store
  3. Biodiesel has a much higher viscosity than straight vegetable oil
  4. Biodiesel has a somewhat lower heating value but higher cetane number and better lubricity
Answer and working

D. Biodiesel has a somewhat lower heating value but higher cetane number and better lubricity

Biodiesel's heating value is somewhat below diesel's; its cetane number, flash point and lubricity are higher; cold-flow behaviour is poorer. Transesterification greatly reduces viscosity compared with straight vegetable oil.

Question 7 · hard

Across Indian states, farm power availability (kW/ha) is positively correlated with land productivity. What is the soundest interpretation?

  1. Every extra kW/ha causes a fixed increase in yield
  2. Power availability has no relationship with productivity
  3. Productivity causes power availability and never the reverse
  4. The association is real, but it does not by itself show that power causes higher yield, because irrigation, soils and income also drive both
Answer and working

D. The association is real, but it does not by itself show that power causes higher yield, because irrigation, soils and income also drive both

Power improves timeliness and quality of operations, so some causal effect is plausible, but cross-sectional correlation is confounded by irrigation, soil fertility and income. Causal claims need designs such as panel data or natural experiments.

Question 8 · hard

Using the block data (total farm power 1989 kW, of which tractors, power tillers, electric motors and diesel engines give 1830 kW), what is the level of mechanisation expressed as the share of mechanical and electrical power?

  1. 92.0%
  2. 8.0%
  3. 1151%
  4. 37.7%
Answer and working

A. 92.0%

Share = 1830/1989 = 92.0%. 8.0% is the animate share; 1151% divides mechanical by animate power instead of by the total; 37.7% counts tractors only.

Question 9 · easy

An operation needs 150 man-hours per hectare. Using an energy equivalent of 1.96 MJ per man-hour, what human energy input is recorded?

  1. 76.5 MJ/ha
  2. 81.7 MJ/ha
  3. 2,352 MJ/ha
  4. 294 MJ/ha
Answer and working

D. 294 MJ/ha

Energy = 150 × 1.96 = 294 MJ/ha. Dividing gives 76.5; 81.7 is the kWh value mislabelled; multiplying by 8 treats man-hours as man-days.

Question 10 · easy

With an energy output of 73,500 MJ/ha and input of 25,000 MJ/ha, what is the net energy?

  1. 48,500 MJ/ha
  2. 98,500 MJ/ha
  3. 2.94 MJ/ha
  4. -48,500 MJ/ha
Answer and working

A. 48,500 MJ/ha

Net energy = output − input = 73,500 − 25,000 = 48,500 MJ/ha. 2.94 is the energy ratio (dimensionless), not MJ/ha. 98,500 MJ/ha adds input to output.

A study plan for Farm Power Sources in ICAR AICE-JRF/SRF

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.

  1. First, the heavy units (68% of the 25 questions): Mechanisation indices (10, 40%); Biomass and biofuels as power sources (4, 16%); Farm power availability (kW/ha) (3, 12%).

    Read the manual chapters for these first and do every worked question you can find on them.

  2. Then the middle band: Wind power as a farm power source (3, 12%); Human power and its limits (2, 8%); Solar power as a farm power source (2, 8%).

    Aim for one sitting per unit, then mixed questions across them.

  3. Then the lighter units: Mechanical power: engines and tractors (1, 4%).

    Learn the definitions, classifications and standard numbers; these units are more often recalled than worked.

  4. Leave time for the hard ones: Human power and its limits (1 hard of 2), Farm power availability (kW/ha) (1 hard of 3), Wind power as a farm power source (1 hard of 3).

    Come back to these after a first pass, untimed, and read every explanation, including for the options you rejected.

  5. Bank the easy marks: Solar power as a farm power source (1 easy of 2); Farm power availability (kW/ha) (1 easy of 3).

    Do these early in revision so they are fast on the day.

  6. Finish timed. Sit the subject as a timed set without notes, mark it, and send each wrong answer back to its unit above.

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