Civil Engineering MCQJE Level Civil Engineering
For a centrifugal pump, the affinity laws state that when speed changes from N1 to N2:
Fluid MechanicsFluid MechanicsMEDIUM
Choose the correct answer
A
Q ∝ N², H ∝ N, P ∝ N³
B
Q ∝ N, H ∝ N², P ∝ N³
C
Q ∝ N, H ∝ N, P ∝ N
D
Q ∝ N³, H ∝ N², P ∝ N
Correct Answer
B. Q ∝ N, H ∝ N², P ∝ N³
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
Affinity laws (pump similarity): Q ∝ N; H ∝ N²; P ∝ N³. If N doubles: flow doubles, head quadruples, power increases 8×. Used for variable speed pumps (VFD control). Also: for geometrically similar pumps of different size at same speed: Q ∝ D³, H ∝ D², P ∝ D⁵.
ScoreCardAI links this solution with subject, topic and difficulty signals so your scorecard can identify weak areas after a full mock test.
Concept shortcut
IS/IRC reference
Common trap
Practice more Civil Engineering questions
This MCQ belongs to JE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.