COMEDK 2025 Evening Solved Paper

Concept:Bulk modulus measures resistance to volume change. For a perfect rigid body, volume never changes, so its bulk modulus is infinite.Explanation:Bulk modulus is defined as $K = -V \frac{dP}{dV}$.For a perfect rigid body, any pressure change $dP$ produces zero volume change ($dV = 0$).Thus $K \to \infty$, so Option C is correct.Check the other options:A: Shear modulus of an ideal liquid is zero (not infinite) because liquids cannot sustain shear stress.B: Steel has a much higher Young’s modulus (~200 GPa) than rubber (~1 MPa), so steel is more elastic (stiffer).D: An ideal (incompressible) liquid also has infinite bulk modulus (not zero).Only option C is a true statement.Answer:Option C