GATE 2021 BT – Question 60

Fundamentals of Biological Engineering · Bioreaction Engineering: Kinetics of cell growth, substrate utilization and product formation, structured and unstructured models · 2 marks · Numerical answer

A binary feed $F_1$ splits into $F_2$ bypass and $F_3$ separator feed. Separation gives $F_4,F_5$; mixer combines $F_2,F_5$ into $F_6$. Stream compositions are $x_{Ai},x_{Bi}$. If $F_1+F_2=100$ kg/h, the system degrees of freedom is _______.

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Correct answer: 6

Explanation

There are six stream flowrates and six independent binary-composition variables (12 unknowns). Five independent component balances plus the feed-flow constraint provide six equations, leaving six degrees of freedom.