ICAR AIEEA-PG Engineering Fundamentals for Dairy Technologists: practice questions

1 · Engineering drawing and reading plant drawings · easy

In first-angle orthographic projection, where is the plan (top view) placed relative to the front elevation?

1. Above it
2. To its left
3. Superimposed on it
4. Below it

2 · Workshop practice: fitting, welding and sheet-metal work · medium

Which method develops the flat pattern of a square-to-round transition piece for a hopper outlet?

1. Triangulation
2. Parallel-line development
3. Radial-line development
4. Orthographic projection alone

3 · Corrosion and its control in dairy plants · medium

Small, deep holes perforate a stainless tank wall while the surrounding surface looks bright. The tank held brine. The corrosion form is:

1. Uniform corrosion
2. Erosion–corrosion
3. Pitting
4. Galvanic corrosion

4 · Corrosion and its control in dairy plants · medium

Sensitisation of ordinary-carbon austenitic stainless steel occurs when it is held in the range of about:

1. 50–150 °C
2. 1,050–1,150 °C
3. 450–850 °C
4. −20 to 0 °C

5 · Power transmission: belts, gears and couplings · medium

A centrifugal milk pump repeatedly destroys its mechanical seal and bearings within weeks. The first thing to check is:

1. The fat content and temperature of the milk being pumped
2. Alignment of the motor and pump shafts at the coupling
3. The colour of the pump casing paint
4. The tooth count of the motor's cooling fan

6 · DC and AC circuits, three-phase supply · medium

An undersized cable feeding a distant pump motor will mainly cause:

1. Voltage drop and cable heating, so the motor runs hot and weak
2. Higher motor speed and lower current because resistance limits load
3. A rise in supply frequency at the motor
4. No effect, because current is the same everywhere

7 · Electric motors and starters in dairy plants · medium

A 4-pole, 50 Hz induction motor runs at 1,455 rpm. What is its slip?

1. 4.5%
2. 3%
3. 0.3%
4. 97%

8 · Electric motors and starters in dairy plants · medium

With a star–delta starter, the starting current and starting torque compared with direct-on-line starting are:

1. Both reduced to one half
2. Current reduced by √3, torque unchanged
3. Both reduced to one third
4. Both increased by √3

9 · Electric motors and starters in dairy plants · medium

An induction motor started direct-on-line typically draws a starting current of about:

1. 5–8 times full-load current
2. Equal to full-load current
3. Half of full-load current
4. 50 times full-load current

10 · Electrical safety and earthing · medium

Why is the electrical shock risk higher in a dairy processing hall than in an office?

1. Wet skin and floors lower body resistance
2. Dairy equipment runs on direct current only
3. Milk is a perfect electrical insulator
4. Stainless steel cannot be earthed