ECAT Physics — Fluid Dynamics
Fluid Dynamics is part of the Physics section of the UET ECAT (30 of the 100 MCQs). It breaks into 2 subtopics, and we hold 26 ECAT-pattern practice MCQs on it, each with a written explanation. Tap a subtopic below to practise just that.
Subtopics (2)
How Fluid Dynamics is tested
Across the 7 ECAT past papers on ParhaiKrlo, Fluid Dynamics accounts for 11 questions. It appears in all 7, about 1.6 questions a paper. The heaviest was ECAT Past Paper 05, with 3 questions, and the most recent is ECAT Past Paper 07, with 1.
| Paper | Questions |
|---|---|
| ECAT Past Paper 07 | 1 |
| ECAT Past Paper 06 | 2 |
| ECAT Past Paper 05 | 3 |
| ECAT Past Paper 04 | 1 |
| ECAT Past Paper 03 | 2 |
| ECAT Past Paper 02 | 1 |
| ECAT Past Paper 01 | 1 |
Fluid Dynamics MCQs from the ECAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · ECAT Past Paper 07 · Fluid Dynamics
As water falls from a tap, its cross-sectional area decreases according to the:
- A.Equation of continuity
- B.Venturi relation
- C.Bernoulli's equation
- D.None of these
Show answer
Answer: A. Equation of continuity — Water speeds up as it falls, and Av = constant narrows the stream.
- Q2 · ECAT Past Paper 06 · Fluid Dynamics
A mass of a liquid of density ρ is mixed with an equal mass of another liquid of density 3ρ. The density of the mixture is:
- A.ρ
- B.2ρ
- C.(3/2)ρ
- D.4ρ
Show answer
Answer: C. (3/2)ρ — Equal masses: ρ_mix = 2m/(m/ρ + m/3ρ) = 2/(4/3ρ) = (3/2)ρ.
- Q3 · ECAT Past Paper 05 · Fluid Dynamics
As water falls from a tap, its cross-sectional area decreases according to the:
- A.Bernoulli equation
- B.Venturi relation
- C.Equation of continuity
- D.None
Show answer
Answer: C. Equation of continuity — The falling water speeds up, and Av = constant makes the stream narrower.