The GATE Grind

GATE Agricultural Process Engineering: Evaporation and Drying – Previous Year Questions

13 GATE previous year questions on Evaporation and Drying (Agricultural Process Engineering, Agricultural Engineering) with answers and explanations, from every paper.

  1. GATE 2021 AG Q32 (1 mark, Numerical answer) – Fresh potatoes1000 kg are dried from 14% to 93% total solids. Peeling loses7% of original potatoes. Find dried product yield from fresh potatoes in…
  2. GATE 2021 AG Q62 (2 marks, Numerical answer) – Air at 40°C, total pressure101.3 kPa, contains water vapour at 4.0 kPa. Saturation vapour pressure at 40°C is 7.37 kPa. Molecular masses…
  3. GATE 2022 AG Q32 (1 mark, Numerical answer) – A forward-feed triple-effect evaporator takes pineapple juice at 6.3 kg/s and produces 50% concentrate. Steam input is 2.48 kg/s at 121.1°C. Vapour…
  4. GATE 2022 AG Q33 (1 mark, Numerical answer) – An osmo-dehydrated fruit slice has 72% moisture on wet basis. Find moisture on dry basis in percent, to one decimal.
  5. GATE 2022 AG Q62 (2 marks, Numerical answer) – Parboiled paddy dries from free moisture .40 to .02 kg water/kg dry solid. Dry solids99.8 kg; exposed area 4.654 m². Constant drying rate 1.51 kg/(m²…
  6. GATE 2022 AG Q65 (2 marks, Numerical answer) – A dryer recycles10 m³/s exhaust at 70°C,30% RH, humidity ratio .06335 kg/kg dry air. It mixes with 20 m³/s ambient air at 30°C,60% RH, humidity ratio…
  7. GATE 2023 AG Q33 (1 mark, Numerical answer) – A fluidized carrot bed has minimum-fluidization height 1.20 m, diameter .60 m, carrot mass250 kg and solid density1040 kg/m³. Find bed porosity, to…
  8. GATE 2024 AG Q24 (1 mark, Multiple select) – Which mechanisms explain the falling-rate drying period? Select all that apply.
  9. GATE 2024 AG Q35 (1 mark, Numerical answer) – A single-effect evaporator concentrates9090 kg/hour herbal extract from 12% to 20% solids. Feed enters at 300 K and product loss with vapor is…
  10. GATE 2024 AG Q63 (2 marks, Numerical answer) – Mango pulp initially 25°C and 70% wet-basis moisture is dried to 10% wet basis using95°C air. Water latent heat at 95°C is 2250 kJ/kg and pulp cp3.8…
  11. GATE 2025 AG Q32 (1 mark, Numerical answer) – Apple slices dry in the falling-rate period from 65% to 10% dry-basis moisture. Equilibrium moisture is 2% dry basis and drying constant is…
  12. GATE 2026 AG Q45 (2 marks, Multiple choice) – A single-effect evaporator concentrates orange juice so product solids concentration/feed solids concentration=2.7. Feed is 100 kg/h at 30°C, and…
  13. GATE 2026 AG Q46 (2 marks, Multiple choice) – At 60°C dry-bulb temperature, saturated water-vapor pressure is 20 kPa and relative humidity 20%. Atmospheric pressure is 101.325 kPa. Molecular…