120. A fan draws 1.42 m3

per second of air at a static pressure of 2.54 cm of water through a

duct 300 mm diameter and discharges it through a duct of 275 mm diameter. Determine the

static fan efficiency if total fan is 75% and air is measured at 25°C and 760 mm Hg.

A. 50.11% B. 53.69%

C. 65.67% D. 45.34