Practice question
Question
An aluminium rod of length 1.6m and cross-sectional area 2×10−6m2 is compressed by a force of 600N. If the Young's modulus of aluminium is 7×1010N/m2, what is the compression?
Explanation
Young's modulus: Y = FLAΔL. Rearrange: ΔL = FLAY. Substitute: ΔL = 600×1.62×10−6×7×1010 = 9601.4×105≈6.86×10−3m = 6.86mm. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 6.86mm. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.