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ICAR AIEEA-PG Basic Electrical & Electronics Engineering: practice questions

ICAR AIEEA-PG — Agricultural Engineering & Technology (Major Subject Group 10) · India · National Testing Agency for ICAR

Original practice questions written to the published syllabus · not past papers
10worked here, free
28written to this exam in this subject
10syllabus units

About ICAR AIEEA-PG

ICAR AIEEA-PG — Agricultural Engineering & Technology (Major Subject Group 10) is a postgraduate admission exam run by National Testing Agency for ICAR, for candidates in India. Computer-based, 120 minutes, 120 MCQs, +4 / −1, English only (2026 bulletin). One paper for the whole subject group.

Source: icar.org.in.

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

Basic Electrical & Electronics Engineering in ICAR AIEEA-PG

Rapid MCQs on electric motors, instruments and power distribution: instrument types and range extension, two-wattmeter method, star–delta relations, transformer EMF equation, losses and efficiency, rectifier formulas, and earthing and protective devices. One-step numericals at about one minute each.

Circuits, power, transformers, electronic devices and safe wiring: what a farm engineer needs before motors and sensors.

Our 28 ICAR AIEEA-PG questions in this subject: 5 easy, 17 medium, 6 hard, across 10 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 AIEEA-PG and are not shown on any other exam's page.

Question 1 · hard

Three equal 30 Ω resistors connected in delta are to be replaced by an equivalent star. What is the value of each star resistor?

  1. 90 Ω
  2. 10 Ω
  3. 52 Ω
  4. 30 Ω
Answer and working

B. 10 Ω

For a balanced network R_Y = R_Δ/3 = 30/3 = 10 Ω (from R_Y = R_ab·R_ac/(R_ab + R_bc + R_ca) = 900/90). 90 Ω is the reverse (star-to-delta) conversion; 30√3 confuses resistance conversion with the line-to-phase voltage ratio.

Question 2 · easy

Why does an induction motor driving a pump operate at a lagging power factor?

  1. It draws magnetising current that lags the voltage by nearly 90°
  2. Its rotor bars behave as capacitors that store charge each half cycle
  3. Its slip makes the rotor frequency higher than the supply frequency
  4. Its stator copper losses shift the current ahead of the supply voltage
Answer and working

A. It draws magnetising current that lags the voltage by nearly 90°

The motor needs a magnetising current to set up the air-gap flux; this component is almost purely inductive and lags the voltage, so the total current lags. Rotor bars are not capacitors, rotor frequency is slip times supply frequency (lower, not higher), and resistive losses keep current in phase rather than shifting it ahead.

Question 3 · medium

A pump delivers 20 L/s against a total head of 30 m. Pump efficiency is 70 % and motor efficiency 88 %. What electrical input power does the motor take?

  1. 3.63 kW
  2. 5.89 kW
  3. 8.41 kW
  4. 9.56 kW
Answer and working

D. 9.56 kW

Water power = ρgQH = 1000 × 9.81 × 0.020 × 30 = 5.89 kW. Shaft power = 5.89/0.70 = 8.41 kW; electrical input = 8.41/0.88 = 9.56 kW. 5.89 kW is water power only; 8.41 kW stops at the shaft; multiplying by the efficiencies gives a number smaller than the water power, which is impossible.

Question 4 · hard

Three 50 Ω heating elements of a grain dryer are connected to a 400 V three-phase supply. What total power do they take in star and in delta?

  1. 3200 W in star; 9600 W in delta
  2. 3200 W in both connections
  3. 1067 W in star; 3200 W in delta
  4. 9600 W in star; 3200 W in delta
Answer and working

A. 3200 W in star; 9600 W in delta

Star: each element sees 400/√3 = 231 V, P = 3 × 231²/50 = 400²/50 = 3200 W. Delta: each sees 400 V, P = 3 × 400²/50 = 9600 W. Delta takes three times the star power. Reversing them, or assuming equal power, are the usual slips; 1067 W treats the star total as one element's share.

Question 5 · hard

A transformer has an iron loss of 0.3 kW and a full-load copper loss of 1.8 kW. At what fraction of full load is its efficiency a maximum?

  1. 40.8 %
  2. 16.7 %
  3. 245 %
  4. 100 %
Answer and working

A. 40.8 %

Maximum efficiency occurs where copper loss equals iron loss: x² × 1.8 = 0.3, so x = √(0.3/1.8) = 0.408 = 40.8 % of full load. 16.7 % forgets that copper loss varies with the square of load; 245 % inverts the ratio; efficiency is not necessarily greatest at full load.

Question 6 · medium

In the two-wattmeter method on a balanced three-phase load, one wattmeter reads zero. What is the power factor?

  1. Zero
  2. 1.0
  3. 0.5
  4. 0.866
Answer and working

C. 0.5

tan φ = √3(W₁ − W₂)/(W₁ + W₂); with W₂ = 0, tan φ = √3, φ = 60°, pf = 0.5. At unity pf the two readings are equal; at zero pf they are equal and opposite.

Question 7 · hard

Two 100 kΩ resistors form a divider across 10 V. A voltmeter of 1 MΩ input resistance is connected across the lower resistor. What does it read?

  1. 4.76 V
  2. 9.09 V
  3. 5.00 V
  4. 0.909 V
Answer and working

A. 4.76 V

The meter in parallel with the lower 100 kΩ gives 90.9 kΩ, so V = 10 × 90.9/(100 + 90.9) = 4.76 V. 5.00 V is the true unloaded value; 9.09 V and 0.909 V wrongly treat the meter and one resistor as the whole divider. This loading effect is why sensor circuits are measured with high-input-resistance meters.

Question 8 · medium

A non-inverting amplifier conditioning a soil-moisture sensor uses R_f = 47 kΩ and R_i = 10 kΩ. What is its voltage gain?

  1. −4.7
  2. 5.7
  3. 0.21
  4. 4.7
Answer and working

B. 5.7

Non-inverting gain = 1 + R_f/R_i = 1 + 47/10 = 5.7. 4.7 omits the 1; a negative value is the inverting amplifier; 0.21 inverts the ratio.

Question 9 · medium

Which flip-flop transfers its single data input to its output at the active clock edge, making it the basic storage cell of registers?

  1. The JK flip-flop with J = K = 1
  2. The T flip-flop
  3. The D flip-flop
  4. The SR latch
Answer and working

C. The D flip-flop

The D (data) flip-flop copies D to Q at the clock edge and holds it until the next edge. A T flip-flop toggles; an SR latch has a forbidden input state; a JK flip-flop with J = K = 1 toggles rather than storing a data bit.

Question 10 · medium

Before servicing a grain auger, which procedure is correct?

  1. Switch off at the start button, then confirm the motor has stopped turning
  2. Isolate, lock off, tag, then prove dead with a tested voltage detector
  3. Remove the fuse from the neutral, then confirm the auger is not moving
  4. Ask a colleague to stand by the switch so that nobody turns it on
Answer and working

B. Isolate, lock off, tag, then prove dead with a tested voltage detector

Lockout–tagout means isolating at the isolator, applying a personal lock and tag, and proving dead with a detector checked on a known live source before and after. A stopped motor is not proof of isolation; a neutral fuse leaves the circuit live; a colleague is not a lock.

A study plan for Basic Electrical & Electronics Engineering in ICAR AIEEA-PG

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 (54% of the 28 questions): Electrical measuring instruments (5, 18%); Transformers (4, 14%); Electrical safety (3, 11%); Operational amplifiers (3, 11%).

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

  2. Then the middle band: Semiconductor devices and rectifiers (3, 11%); Single-phase and three-phase supply (3, 11%); AC circuits, phasors and power factor (2, 7%); DC circuits and network theorems (2, 7%).

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

  3. Then the lighter units: Digital logic (2, 7%); House wiring and earthing (1, 4%).

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

  4. Leave time for the hard ones: DC circuits and network theorems (2 hard of 2), Semiconductor devices and rectifiers (1 hard of 3), Single-phase and three-phase supply (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: AC circuits, phasors and power factor (1 easy of 2); Electrical safety (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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