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Stress, Strain and Hooke's Law

Focuses on stress, strain, and Hooke's Law with problems on elastic deformation and material properties. Helps students apply these concepts in physics and engineering contexts.

41 questions

What is the primary reason gases are more compressible than liquids?

Gases have weaker intermolecular forces and larger intermolecular spaces compared to liquids, allowing them to compress significantly under pressure, while liquids’ strong forces resist volume changes. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Weaker intermolecular forces. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.

A brass block of dimensions 0.4m×0.3m×0.1m is subjected to a shearing force of 3×104N. If the shear modulus of brass is

Shear modulus: G = F/AΔx/L. Rearrange: Δx = FLAG. Area: A = 0.4×0.3 = 0.12m2, L = 0.1m. Substitute: Δx = 3×104×0.10.12×3.6×1010 = 30004.32×109≈6.94×10−7m. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 6.94×10−7m. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

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

A water sample of volume 3litres is compressed by a pressure of 4×106N/m2. If the bulk modulus of water is 2.2×109N/m2,

Bulk modulus: B = −pΔVV. Rearrange: ΔVV = −pB = −4×1062.2×109≈−1.82×10−3. Volume: V = 3litres = 3×10−3m3. Change in volume: ΔV = ΔVV×V = −1.82×10−3×3×10−3≈−5.45×10−6m3. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 5.45×10−6m3. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.

Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.

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

Young's modulus: Y = StressStrain. Stress: Stress = Y×Strain = 7×1010×2×10−4 = 1.4×107N/m2. Force: F = Stress×A = 1.4×107×2×10−6 = 28N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 28N. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.

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

A steel wire of length 2.6m and cross-sectional area 2×10−6m2 is stretched by 0.52mm. If the Young's modulus of steel is

Young's modulus: Y = FLAΔL. Rearrange: F = YAΔLL. Substitute: ΔL = 0.52×10−3m. F = 2×1011×2×10−6×0.52×10−32.6 = 2082.6 = 80N. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 80N. This satisfies dimensional consistency and physical conditions given, so option D is scientifically correct.

Ref: University Physics, Chapter 17: Thermal Expansion.

A copper wire of length 2.8m and cross-sectional area 2×10−6m2 is stretched by a force of 160N. If the Young's modulus o

Young's modulus: Y = FLAΔL. Rearrange: ΔL = FLAY. Substitute: ΔL = 160×2.82×10−6×1.1×1011 = 4482.2×105≈2.04×10−3m = 2.04mm. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 2.04mm. 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 2.0m and cross-sectional area 2.5×10−6m2 is stretched by a force of 250N. If the Young's modulus

Stress: Stress = FA = 2502.5×10−6 = 1×108N/m2. Young's modulus: Y = StressStrain. Strain: Strain = StressY = 1×1082×1011 = 5×10−4. As per NCERT, applying relevant law/formula with correct units and sign convention leads to 5×10−4. This satisfies dimensional consistency and physical conditions given, so option A is scientifically correct.

Ref: University Physics, Chapter 17: Thermal Expansion.