COMSATS Physics — Fluid Dynamics
Fluid Dynamics is part of the Physics section of the NTS NAT-IE test COMSATS admits on (10 of the 90 MCQs). It breaks into 2 subtopics, and we hold 15 NAT-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 NAT-pattern papers on ParhaiKrlo, Fluid Dynamics accounts for 3 questions. It appears in 3 of them, about 1 questions a paper. The heaviest was COMSATS Past Paper 05, with 1 question.
| Paper | Questions |
|---|---|
| COMSATS Past Paper 05 | 1 |
| COMSATS Past Paper 04 | 1 |
| COMSATS Past Paper 02 | 1 |
Fluid Dynamics MCQs from the NAT-pattern papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · COMSATS Past Paper 05 · Fluid Dynamics
Water flows at 2 m/s through a pipe of cross-sectional area 4 cm². The pipe narrows to 1 cm². What is the speed of the water in the narrow part?
- A.2 m/s
- B.8 m/s
- C.4 m/s
- D.0.5 m/s
Show answer
Answer: B. 8 m/s — A₁v₁ = A₂v₂ → 4 × 2 = 1 × v₂ → v₂ = 8 m/s.
- Q2 · COMSATS Past Paper 04 · Fluid Dynamics
Stokes' law gives the drag force on a small sphere of radius r moving slowly at speed v through a fluid of viscosity η as:
- A.F = ½ρv²
- B.F = 4πηrv
- C.F = 6πηrv
- D.F = 6πηr²v
Show answer
Answer: C. F = 6πηrv — Stokes' law: F = 6πηrv.
- Q3 · COMSATS Past Paper 02 · Fluid Dynamics
According to Bernoulli's principle, where the speed of a flowing fluid increases, its pressure:
- A.decreases
- B.becomes zero
- C.stays the same
- D.increases
Show answer
Answer: A. decreases — P + ½ρv² is constant along a streamline, so higher v means lower P.