If a single tube pass heat exchanger is converted to two passes; for the same flow rate, the pressure drop per unit length in tube side will __________ times.
A
Increase by 1.8
B
Decrease by 2<sup>2</sup>
C
Increase by 2<sup>1.6</sup>
D
None of these
Correct Answer: Increase by 2<sup>1.6</sup>