Water is discharged from vertical side of a tank through a circular orifice of diameter 2 cm under laminar flow conditions. The water surface in the tank is maintained at constant level above the center of the orifice. If the fluid jet has a diameter of 1.6 cm at its vena contracta, then the coefficient of contraction is ________________ (rounded off to two decimal places).

Question

Accepted Answer

The correct answer is 0.63 to 0.65. GATE 2026 official key: 0.63 to 0.65. Coefficient of contraction Cc = A_jet/A_orifice = (d_jet/d_orifice)² since both cross-sections are circular; Cc = (1.6/2)² = 0.64.