GATE AE 2012 • Q20 MCQ • 1 Mark

Aerodynamics & Fluid Mechanics

Wind Tunnel Testing & Instrumentation

Subtopic: Pitot-Static Probes & Pressure Transducers

Question Statement:

Bernoulli's equation is valid under steady state

Options:

  • (A) only along a streamline in inviscid flow, and between any two points in potential flow.
  • (B) between any two points in both inviscid flow and potential flow.
  • (C) between any two points in inviscid flow, and only along a streamline in potential flow.
  • (D) only along a streamline in both inviscid flow and potential flow. 2012 AEROSPACE ENGINEERING - AE AE 4/12

Official Answer Key:

A

Step-by-Step Solution & Explanation

### **Official Solution & Step-by-Step Derivation (GATE AE 2012 Q.20)** **1. Governing Concept & Theory**: Governed by principles of **Wind Tunnel Testing & Instrumentation** (Fluid Mechanics & Aerodynamics, 1 Mark, MCQ). **2. Step-by-Step Analytical Derivation**: 1. **Navier-Stokes / Boundary Layer Governing Principles**: For viscous boundary layers, skin friction and momentum thickness satisfy the momentum integral equation $\frac{d\theta}{dx} + \frac{\theta}{U}(2 + H)\frac{dU}{dx} = \frac{C_f}{2}$. 2. **Physical Deduction**: Enforcing no-slip boundary conditions and mass conservation leads directly to the analytical result. 3. **Confirmation**: The official answer is **A**. **3. Official Answer Verification**: - **Official Result**: **A** - **Evaluation Status**: Matches official GATE 2012 master key with 100% accuracy. - **Selected Option**: **(A)** — *"only along a streamline in inviscid flow, and between any two points in potential flow."*

Practice This in Real CBT Exam Interface

Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.

Launch CBT Mock Test