Practice question

Given: An aluminium block of dimensions 0.4 m × 0.3 m × 0.1 m is subjected to a shearing force of 4 × 10⁴ N . If the shear modulus of aluminium is 2.5 × 10¹⁰ N/m², what is the shear strain? These values define the system as per NCERT data. Formula: Shear modulus: G = fracShear stressShear strain. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Shear stress: Shear stress = F/A, A = 0.4 × 0.3 = 0.12 m² . Shear stress: 4 × 10⁴/0.12 approx 3.33 × 10⁵ N/m² . Shear strain: Shear strain = fracShear stressG = frac3.33 × 10⁵².5 × 10¹⁰ approx 1.33 × 10⁻⁵. Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.