Question

As the depth of the river increases, the velocity of flow

• A. increases
• B. decreases
• C. remains unchanged
• D. may increase or decrease

Answer 1

Answer: (B)

decreases

Answer 2

The velocity gradient of water flow in the river $\left(\frac{ dv }{ dx }\right)$ is constant, that is, the velocity of river flow increases with increasing height above the water bed. As a result, the water flow speed on the bed is zero, and that on the river's surface is maximum.