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#stress calculation

11 public questions tagged with this topic.

A brass wire of length 1.8m and cross-sectional area 2.5×10−6m2 is stretched by a force producing a strain of 2×10−4. If

Young's modulus: Y = StressStrain. Stress: Stress = Y×Strain = 9×1010×2×10−4 = 1.8×107N/m2. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 1.8×107N/m2. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

An aluminium rod of length 1.4m and cross-sectional area 2×10−6m2 is compressed by a force producing a stress of 3×107N/

Young's modulus: Y = StressStrain. Strain: Strain = StressY = 3×1077×1010≈4.29×10−4. Compression: ΔL = Strain×L = 4.29×10−4×1.4≈6×10−4m = 0.6mm. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 0.6mm. This satisfies dimensional consistency and physical conditions given, so option D is scientifically correct.

Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.

A steel wire of length 2.7m and cross-sectional area 3×10−6m2 is stretched by a force of 450N. If the Young's modulus of

Stress: Stress = FA = 4503×10−6 = 1.5×108N/m2. Young's modulus: Y = StressStrain. Strain: Strain = StressY = 1.5×1082×1011 = 7.5×10−4. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 7.5×10−4. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: University Physics, Chapter 17: Thermal Expansion.