The diameter of the nozzle (d) for maximum transmission of power is given by (where D = Diameter of pipe, f = Darcy 's coefficient of friction for pipe, and l = Length of pipe )

• A. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/171-255-1.png">
• B. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/171-255-2.png">
• C. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/171-255-3.png">
• D. <img src="/_files/images/mechanical-engineering/hydraulics-and-fluid-mechanics/171-255-4.png">