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Orifices: coefficient of resistance (head-loss coefficient) — select the correct definition Choose the ratio that defines the coefficient of resistance for an orifice.

Q: Orifices: coefficient of resistance (head-loss coefficient) — select the correct definition Choose the ratio that defines the coefficient of resistance for an orifice.

Concept/Approach Coefficient of resistance (head-loss coefficient) Cr quantifies energy loss: Cr = hloss / h. Other coefficients: Cv = va/vth, Cc = ajet/aorifice, Cd = Qa/Qth. Final Answer Loss of head in the orifice divided by the available head.

Difficulty: Easy

Actual velocity at vena contracta / Theoretical velocity
Area of jet at vena contracta / Area of orifice
Loss of head in the orifice / Available head at the orifice exit
Actual discharge / Theoretical discharge

Correct Answer: Loss of head in the orifice / Available head at the orifice exit

Explanation:

Concept/Approach

Coefficient of resistance (head-loss coefficient) C_r quantifies energy loss: C_r = h_loss / h.
Other coefficients: C_v = v_a/v_th, C_c = a_jet/a_orifice, C_d = Q_a/Q_th.

Final Answer
Loss of head in the orifice divided by the available head.

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