Consider this figure where diameters D3 D1 D2 and point C i

Consider this figure where diameters D3 > D1> D2 and point C is a pump. Which of the following is true about the velocity in pipe D2 (between B and C) and velocity in pipe D2 (between C and D)? D1 D2 D3 velocity in pipe D2 (between B and C) velocity in pipe D2 (between C and D) velocity in pipe D2 (between B and C)velocity in pipe D2 (between C and D) Not enough information given

Solution

Velocity in pipe D2 between B and C=Velocity in pipe D2 between C and D

Explanation:

Discharge in pipe BC and CD is same. As cross section is same for both BC and CD, to satisfy continuity equation (Discharge=Area of cross section* velocity) in both parts BC and CD, the velocities will be same.

Even though there is a pump at C which only increases static head of water. Total pressure at location CD will be more than that at BC due to the pump, but dynamic head will be same to satisfy continuity of flow. Hence velocities will be same.