GATE Dairy and Food Engineering: Heat and Mass Transfer – Previous Year Questions
21 GATE previous year questions on Heat and Mass Transfer (Dairy and Food Engineering, Agricultural Engineering) with answers and explanations, from every paper.
- GATE 2021 AG Q19 – For one-dimensional radial conduction,r-n r(krn rT)+E= C p tT. What is n for a sphere?
- GATE 2021 AG Q46 – Match P pipe-in-pipe;Q shell-and-tube;R1–2 shell-and-tube;S crossflow exchanger, to 1 air cooling,2 simultaneous co-/counter-current exchange,3 large…
- GATE 2021 AG Q47 – A 30 µm membrane of area 3 m² removes NaCl at steady state. Film coefficients are1×10⁻⁶ and 3×10⁻⁷ m/s;membrane permeability9×10⁻⁶ m/s. Feed…
- GATE 2021 AG Q65 – A .10 m food block is heated on one side with film coefficient70 W/(m²°C),cooled on the other with 100 W/(m²°C). Conductivity .2 W/(m°C),area 1…
- GATE 2022 AG Q34 – Potato solids have specific heat 837.36 J/(kg K). Find the specific heat of potatoes containing 85% moisture on wet basis, in J/(kg K), to two…
- GATE 2022 AG Q64 – A freezer wall comprises120 mm brick,75 mm concrete and 50 mm cork. Conductivities are .69,.76,.043 W/(m K). Outside/inside surface temperatures24…
- GATE 2023 AG Q28 – Which heat exchanger does not require an LMTD configuration correction factor?
- GATE 2023 AG Q46 – An ice-cream freezer has three scraper blades, temperature difference30°C, ice density917 kg/m³,latent heat335 kJ/kg and U=2000 kJ/(m²·hour·°C).…
- GATE 2023 AG Q48 – Which forced-convection dimensionless-number statements are correct?
- GATE 2023 AG Q63 – Oil in a .6 m pipe has wall shear stress12.5 Pa, pressure drop300 Pa and flow .25 m³/s. Find viscosity as n×10⁻³ Pa·s, reporting n to three decimals.
- GATE 2023 AG Q65 – Copper and steel balls of diameters d₁,d₂ start at 200°C and both reach120°C after the same time in 30°C air. Bi<.1. Copper density8950 kg/m³,cp383…
- GATE 2024 AG Q20 – For cylindrical pipe insulation with conductivity k and outer convection coefficient h o,find the critical insulation radius r cr.
- GATE 2024 AG Q61 – A steam-jacketed kettle holds250 kg liquid food with specific heat3.1 kJ/(kg·K). Steam is 121°C, heat-transfer coefficient2 kW/(m²·K),area .15 m².…
- GATE 2024 AG Q62 – Countercurrent juice pasteurization uses juice flow .3 kg/s, cp3.8 kJ/(kg·K),inlet30°C. Water flow is .4 kg/s, cp4.2 kJ/(kg·K),inlet97°C, outlet65°C.…
- GATE 2025 AG Q35 – Three identical metal wires AC, BC, CD have equal length, diameter and thermal conductivity. Heat flows from A and B to C and from C to D. A and B are…
- GATE 2025 AG Q61 – An N 2–He mixture in a pipe is at 1 atm and 298 K. Nitrogen partial pressures at points .22 m apart are 60.80 and 20.31 kPa. The diffusivity is…
- GATE 2025 AG Q62 – A countercurrent concentric heat exchanger receives milk at 25°C and water at 82.5°C. Water flow is 1.2 kg/s. Inner-pipe diameter is 60 mm, length 6…
- GATE 2026 AG Q26 – Which quantity is dimensionless?
- GATE 2026 AG Q27 – The water activity of a food equals the fractional relative humidity of air in equilibrium with that food. At the same specified temperature, how does…
- GATE 2026 AG Q30 – Which dimensionless number relates specific heat, dynamic viscosity and thermal conductivity?
- GATE 2026 AG Q43 – A 2 mm diameter electric wire is covered by 2 mm thick plastic of conductivity 0.5 W/(m·K). Air is at 320 K with external convection coefficient 25…