For smooth entry of water in a canal, the angle between head regulator and water is generally kept A. 80° B. 90° C. 110° D. 120°

The correct answer is: 90°.

The angle between the head regulator and the water should be 90°

for smooth entry of water in a canal. This is because at 90°, the water will flow into the canal without any turbulence or splashing. If the angle is less than 90°, the water will flow into the canal at an angle and will create turbulence. If the angle is greater than 90°, the water will flow into the canal at a sharp angle and will create splashing.

Here is a diagram that illustrates the different angles and their effects on the flow of water:

[Diagram of a canal with a head regulator at different angles]

As you can see, the water flows smoothly into the canal when the angle is 90°. However, when the angle is less than 90°, the water flows into the canal at an angle and creates turbulence. When the angle is greater than 90°, the water flows into the canal at a sharp angle and creates splashing.

Therefore, the angle between the head regulator and the water should be 90° for smooth entry of water in a canal.