What will happen to the co efficient of discharge if the tube is shorter than the standard length or the head causing the flow is relatively high?

If the tube is shorter than the standard length, the coefficient of discharge (Cd) may increase due to reduced friction losses and a more streamlined flow, potentially leading to higher flow rates. Conversely, if the head causing the flow is relatively high, the increase in velocity can lead to turbulence, which may decrease the Cd due to increased energy losses. Ultimately, both factors can influence the Cd, but the net effect will depend on the specific flow conditions and tube characteristics.