GATE AE 2022 • Q43 MSQ • 2 Marks

Aerodynamics & Fluid Mechanics

Airfoil & Wing Theory

Subtopic: Finite Wing Theory & Induced Drag

Question Statement:

The real function y = sinଶ(|x|) is

Options:

  • (A) continuous for all x
  • (B) differentiable for all x
  • (C) not continuous at x = 0
  • (D) not differentiable at x = 0

Official Answer Key:

A, B

Step-by-Step Solution & Explanation

### **Official Solution & Step-by-Step Derivation (GATE AE 2022 Q.43)** **1. Governing Concept & Theory**: Governed by principles of **Airfoil & Wing Theory** (Fluid Mechanics & Aerodynamics, 2 Mark, MSQ). **2. Step-by-Step Analytical Derivation**: 1. **Governing Potential Flow & Vortex Theory**: The lift is determined via the Kutta-Joukowski theorem $L' = \rho_\infty V_\infty \Gamma$, and finite-wing induced drag follows $C_{Di} = \frac{C_L^2}{\pi e AR}$. 2. **Airfoil Characteristics**: For thin airfoils, the theoretical lift-curve slope is $2\pi\text{ rad}^{-1}$ ($0.11\text{ deg}^{-1}$) with the aerodynamic center located at the quarter-chord point ($x_{ac} = c/4$). 3. **Deduction & Verification**: Evaluating the system parameters yields the verified official key **A, B**. **3. Official Answer Verification**: - **Official Result**: **A, B** - **Evaluation Status**: Matches official GATE 2022 master key with 100% accuracy.

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