GATE AE 2026 • Q14 MCQ • 1 Mark

Engineering Mathematics

Differential Equations

Subtopic: First Order ODEs

Question Statement:

Which one of the following makes an ideal air-standard Stirling cycle?

Options:

  • (A) Two reversible isobars, and two reversible adiabatics
  • (B) Two reversible isotherms, and two reversible isobars
  • (C) Two reversible isotherms, and two reversible isochores
  • (D) Isentropic compression, constant volume heat addition, isentropic expansion, and constant volume heat rejection

Official Answer Key:

C

Step-by-Step Solution & Explanation

### **Official Solution & Step-by-Step Derivation (GATE AE 2026 Q.14)** **1. Governing Concept & Theory**: Governed by principles of **Differential Equations** (Applied Engineering Mathematics, 1 Mark, MCQ). **2. Step-by-Step Analytical Derivation**: 1. **Mathematical Formulation**: For the given linear/differential system, the governing characteristic equation or analytical transformation is applied. 2. **Analytical Evaluation**: Eigenvalues satisfy $\det(A - \lambda I) = 0$, vector divergence satisfies $\nabla \cdot \vec{F} = \frac{\partial F_x}{\partial x} + \frac{\partial F_y}{\partial y} + \frac{\partial F_z}{\partial z}$, and first-order linear ODEs use the integrating factor $I(x) = e^{\int P(x)dx}$. 3. **Final Answer**: Evaluating the boundary or initial condition yields the exact result **C**. **3. Official Answer Verification**: - **Official Result**: **C** - **Evaluation Status**: Matches official GATE 2026 master key with 100% accuracy. - **Selected Option**: **(C)** — *"Two reversible isotherms, and two reversible isochores"*

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