Question

The proportional perimeter of a circular sewer section when the sewage is running partially full is ___ .

• A. \( \frac{\theta}{360^\circ} \)
• B. \( \frac{\pi D}{360^\circ} \)
• C. \( \frac{\pi D \theta}{360^\circ} \)
• D. \( \frac{360^\circ}{\pi D} \)

Hint:

For partially full circular sewer systems, always use the angle \( \theta \) to calculate the submerged perimeter, as it directly influences the flow characteristics.

Answer 1

The Correct Option is A

When a circular sewer is partially full, the proportional perimeter is determined by the angle \( \theta \) that represents the arc length submerged by the flow of sewage. This angle is measured in degrees and represents the fraction of the circular perimeter that is in contact with the flowing sewage. The formula \( \frac{\theta}{360^\circ} \) gives the proportion of the perimeter submerged.