Question

The coefficient of velocity, c_v­ for an orifice is 0.98. Head loss at the orifice for discharge under a head of 200 cm is:

1. 0.8 cm
2. 8 cm
3. 80 cm
4. 2 cm

Answer 1

Correct Answer - Option 2 : 8 cm

Concept:

Head loss at the orifice for discharge under a given head is given by

H f = H (1- C_v2) 

Where H _f is head loss, H is head , cv­ is coefficient of velocity.

Calculation:

Given:

H = 200 cm,  cv­ = 0.98

H f = H (1- C_v2) 

H _f = 200 (1- 0.98²) 

H f = 7.92 cm.