Consider a pair of point vortices with clockwise circulation Γ each. The distance
between their centers is a, as shown in the figure. Assume two-dimensional,
incompressible, inviscid flow. Which one of the following options is correct?
Options:
(A) The vortices translate downwards together with a velocity
Γ
2𝜋a .
(B) The vortices translate upwards together with a velocity
Γ
2𝜋a .
(C) The vortices rotate clockwise around each other about their centroid O.
(D) The vortices rotate counter-clockwise around each other about their centroid O.
Official Answer Key:
A
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE AE 2025 Q.20)**
**1. Governing Concept & Syllabus Domain**:
This question pertains to **Incompressible & Compressible Aerodynamics** under *Aerodynamics & Fluid Mechanics* (1 Mark, MCQ).
**2. Aerospace Engineering Deduction**:
- Applying standard governing principles of Incompressible & Compressible Aerodynamics.
- Option **(A)** matches the analytical derivation and official criteria.
**3. Final Answer**:
Correct Option is **(A)**.
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.