🧪 NPCIL Interview Experience – Chemical Engineering (GATE 2025)

• Name: Bhaskar
• Date: 13th June 2025
• Duration: 35–40 minutes
• Venue: MAPS Guest House, Kalpakkam (Chennai)
• Panel: 7 members – 5 male and 2 female

Interview Summary:

Upon entering the interview room, I was greeted politely and asked to take a seat. The interview began without delay, and the panel quickly moved into technical questioning based on my background and interests.

Questions & My Responses:

1. Basic Introduction:
   • Panel: “So, your name is… Bhaskar?”
   • “You are pursuing your Bachelors in… IET Lucknow?”
   • I responded confidently to both.
2. Favourite Subjects:
   • They asked me to list my four favourite subjects.
   • I answered: Heat Transfer (HT), Mass Transfer (MT), Fluid Mechanics (FM), and Chemical Reaction Engineering (CRE).
3. Bernoulli’s Equation (Application-Based):
   • Asked to explain an industrial application of Bernoulli’s Equation.
   • I was provided a whiteboard and marker. I drew the diagram, wrote the equation, and explained its usage.
   • They seemed satisfied with the clarity and depth of explanation.
4. Heat Transfer Slab + Boundary Layer Concept:
   • Asked to draw a slab of thickness ‘t’ with hot and cold fluids on either side.
   • Then asked to illustrate the boundary layer and explain the concept.
   • There were a few cross-questions, which I handled reasonably well.
5. Flow Rate vs Pressure Drop Question (Paper-Based):
   • Given a problem involving 5 LPM flow rate and two pressure values (5 and 15) in different setups.
   • They asked for pressure difference and related parameters.
   • They followed up with questions on Darcy’s Law and the Hagen-Poiseuille equation. I attempted to answer, though they seemed somewhat unsatisfied.
6. Pumps & Flow Control:
   • Asked: “How many types of pumps are used in the industry?”
   • Followed by:
     • Working principle of a centrifugal pump
     • When to use positive displacement pumps vs centrifugal pumps
     • Which pump suits a constant flow rate application and why?
   • I answered confidently with concepts from Fluid Mechanics.
7. Refrigeration & Air Conditioning:
   • Asked to explain the refrigeration cycle.
   • They further probed:
     • Main parts of an AC system
     • Difference between an AC and an air cooler
   • I tried answering but realized they were expecting more precise industry-level responses, and I couldn’t fully satisfy them here.
8. Process Controllers:
   • Asked about P, PI, and PID controllers and their differences.
   • Follow-up: “If you’re controlling the flow level in a tank, which controller would you use and why?”
   • I explained control actions with some justification, but again sensed that my answers didn’t completely meet their expectations.
9. Pump Curve Confusion:
   • Asked to draw the H-Q (Head vs Flow rate) curve for a positive displacement pump.
   • Unfortunately, I mistakenly drew the centrifugal pump curve.
   • They caught the mistake and asked me to differentiate the two, along with more follow-up questions. I recovered and clarified the difference.
10. Pressure Valves:

• Concluding questions were on pressure valves:
  • Types of valves used in industries
  • Purpose and selection criteria
• I answered with examples and industrial usage contexts.

Final Remarks:

• The interview was entirely technical, covering major domains of core Chemical Engineering.
• Strengths: Confident responses in fluid mechanics, heat transfer, and practical pumping systems.
• Areas for Improvement: Needed more clarity and deeper understanding in refrigeration systems, PID control applications, and pressure valve mechanisms.
• Result: Awaiting outcome.