ICAR AICE-JRF/SRF (PhD): Dairy Chemistry, Dairy Microbiology, Dairy Technology, Dairy Engineering · India · NTA for ICAR
Original practice questions written to the published syllabus · not past papersConstruction, operation, care and sizing of the machines in a milk plant: tanks, separators, homogenisers, pasteurisers, sterilisers and fillers.
In the exams: ICAR AIEEA-PG group 17 Unit II (homogeniser, pasteuriser, steriliser, mixing and agitation); ICAR AICE subject 38 Unit 5
ICAR AICE-JRF/SRF (PhD) — Dairy Engineering (38)
Unit 5: dairy processing equipment, aseptic processing and packaging equipment, storage tanks (horizontal and vertical silos, insulation, nozzles and mountings), construction codes and design for heat exchangers. Unit 4: heat exchangers (LMTD, effectiveness). Expect design calculations and comparisons of equipment types.
How our questions for ICAR AICE-JRF/SRF spread across the units of Dairy Processing Equipment. Difficulty: 7 easy, 35 medium, 20 hard.
| Sanitary design features and materials of dairy equipment | 7 | |
| Retorts and in-container sterilisers | 6 | |
| UHT plants: direct steam injection and infusion; indirect systems | 6 | |
| Centrifugal separators and clarifiers | 5 | |
| Homogenisers: triplex pump, valves, two-stage operation, care | 5 | |
| Plate heat exchangers: regeneration, holding tube, flow diversion valve | 5 | |
| Mixing and agitation equipment | 5 | |
| Milk storage tanks and silos | 4 | |
| Tubular and scraped-surface heat exchangers | 4 | |
| Butter churns and continuous butter makers | 4 | |
| Cheese vats, curd makers and moulding systems | 4 | |
| Filling and packaging machines | 4 | |
| Ice cream freezers | 3 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
A separator bowl spins at 6,000 rpm. At a radius of 0.25 m, roughly how many times gravity (9.81 m/s²) is the centrifugal acceleration?
A. About 10,061 g
ω = 2π × 6000 ÷ 60 = 628.3 rad/s; rω² = 0.25 × 628.3² = 98,696 m/s² ≈ 10,061 g. The other figures forget 2π, use rpm instead of rad/s, or use ω instead of ω².
Further reading: Tetra Pak, Dairy Processing Handbook
If agitator speed is doubled with the same impeller, by what factor does power rise (turbulent flow, P ∝ N³)?
D. 8
2³ = 8. 2 assumes linear; 4 squares; 32 uses the D⁵ exponent.
Further reading: Singh and Heldman, Introduction to Food Engineering
What is the purpose of a silo air vent with filter?
A. Prevent vacuum or pressure damage
Blocked vents can collapse tanks, for example when hot CIP solution cools.
Further reading: Tetra Pak, Dairy Processing Handbook
Why can an outdoor silo collapse after hot CIP if its vent is blocked?
A. Cooling vapour creates a vacuum
Contraction of hot vapour lowers internal pressure.
Further reading: Tetra Pak, Dairy Processing Handbook
Why are steam barriers fitted on valves in aseptic systems?
B. Keep shaft seals sterile
Steam around seals blocks microbial ingress.
Further reading: Tetra Pak, Dairy Processing Handbook
Static mixers blend streams by:
B. Fixed elements dividing the flow
Fixed elements split and recombine the flow, so no moving parts are needed.
Further reading: Tetra Pak, Dairy Processing Handbook
In continuous butter makers, butter grains form in:
C. A high-speed beater cylinder
Grains form within seconds.
Further reading: Tetra Pak, Dairy Processing Handbook
The vacuum section of a continuous butter maker:
D. Removes air for a denser butter
Air removal improves body and keeping quality.
Further reading: Tetra Pak, Dairy Processing Handbook
Pasta filata curd is worked in:
D. Cooker-stretchers
Augers knead curd in hot water.
Further reading: Tetra Pak, Dairy Processing Handbook
Why is the filling zone treated as a high-hygiene area?
B. Product is exposed after its last heat treatment
Post-process contamination is the main risk.
Further reading: Tetra Pak, Dairy Processing Handbook
Ten here, 62 in the app. The Laisha app has every practice question we have written to ICAR AICE-JRF/SRF in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
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