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Turbomachinery performance parameter: unit discharge For a turbine operating under head H with discharge Q, express the unit discharge (i.e., the discharge referred to a head of 1 m). Choose the correct formula.

Difficulty: Easy

Q · √H
Q / H
Q / √H
Q / H^(3/2)

Correct Answer: Q / √H

Explanation:

Given

Actual discharge through the turbine = Q.
Operating head = H.

Concept

Unit quantities are values reduced to a reference head of 1 m. For discharge, the scaling with head is proportional to √H (from continuity with velocity ∝ √H), hence:

FormulaUnit discharge, Q_u = Q / √H

ChecksIf H increases while geometry is similar, Q increases roughly with √H, so Q/√H stays about constant.

Final AnswerQ / √H.

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