Question

Under no wind conditions and at constant operating pressure the 100% overlapping is obtained when sprinklers are spaced at _____.

• A. half of radius of throw
• B. radius of throw
• C. twice of radius of throw
• D. thrice of radius of throw

Hint:

Important sprinkler spacing relation: \[ \boxed{ \text{100% overlap spacing} = \text{Radius of throw} } \] Remember:
• Smaller spacing \(\rightarrow\) Better uniformity
• Larger spacing \(\rightarrow\) Dry patches

Answer 1

The Correct Option is B

Concept: In sprinkler irrigation systems, water is distributed in circular patterns around each sprinkler nozzle. For efficient irrigation:
• Water application must be uniform
• Dry spots should be avoided
• Overlapping between sprinklers is necessary The spacing between sprinklers is decided based on:
• Radius of throw
• Wind condition
• Operating pressure
• Sprinkler discharge pattern Under ideal no-wind conditions, maximum uniformity is obtained when sprinkler wetted areas overlap completely.

Step 1: Understanding radius of throw. The radius of throw is: \[ \boxed{ \text{Distance from sprinkler to farthest point wetted} } \] If: \[ R = \text{radius of throw} \] then the sprinkler wets a circular area of radius \(R\).

Step 2: Understanding overlap concept. Sprinklers are never spaced at the full diameter because:
• Water distribution near the edge is less uniform
• Edge regions receive lower precipitation Hence overlapping is required. For 100% overlap: \[ \boxed{ \text{Spacing} = \text{Radius of throw} } \] This ensures:
• Complete overlap of low-intensity edge zones
• Uniform precipitation distribution

Step 3: Analyzing the options. Option (A): Half radius spacing would create excessive overlap and is not the standard condition for 100% overlap. Hence: \[ \boxed{\text{Option (A) is incorrect}} \] Option (B): Spacing equal to radius of throw gives 100% overlap under no-wind condition. Hence: \[ \boxed{\text{Option (B) is correct}} \] Option (C): Twice the radius equals full diameter spacing, causing poor uniformity. Hence: \[ \boxed{\text{Option (C) is incorrect}} \] Option (D): Three times radius is excessively large spacing and leaves dry areas. Hence: \[ \boxed{\text{Option (D) is incorrect}} \] Final Conclusion: Under no wind condition and constant operating pressure: \[ \boxed{ \text{100% overlap occurs when spacing equals radius of throw} } \] Hence the correct answer is: \[ \boxed{ (B)\ \text{radius of throw} } \]