Mechanical Properties of Solids - Practice Questions with Answers
84 free MCQs on Mechanical Properties of Solids, each with its own worked answer and explanation. Stress, strain, Hookes law, and the elastic moduli that describe how solids deform and recover under load.
84 practice questions on Mechanical Properties of Solids, sorted Easy → Hard. Try each one first, then open its answer page for the worked explanation. Want the full theory first? Read the Mechanical Properties of Solids notes.
A typical stress-strain curve: the initial straight line (Hooke's Law region, slope = Young's modulus) ends at the elastic limit; beyond the yield point, deformation becomes permanent, peaking at the ultimate tensile strength before the wire finally fractures.
Easy - 25 questions
Q1.
The ratio of shear stress to shear strain is called the:
Two wires of the same material have radii in ratio 2:1 and lengths in ratio 1:2. If stretched by the same force, the ratio of their elongations (ΔL<sub>1</sub>:ΔL<sub>2</sub>) is:
A solid sphere of volume V is submerged in a fluid such that pressure increases by ΔP, causing a volume decrease ΔV. If bulk modulus is B, which expression is correct?
Two springs of force constants k1 and k2 connected in series behave like a single spring of effective Youngs-modulus analog with stiffness k. Which formula gives k?
A wire stretches by 1 mm under a certain load. Another wire of the same material, but with double the length and double the diameter, stretches under the same load by:
A rubber cord has a cross-sectional area 1 mm² and total unstretched length 10 cm. It is stretched to 12 cm. If Youngs modulus of rubber is 5 × 10⁸ Pa, the tension in the cord is:
A beam supported at both ends sags under its own weight. To minimize the sag (depression) without significantly increasing material used, engineers use a beam with cross-section shaped like:
A A solid circular rod during normal conditions
B An I-shaped (I-beam) cross-section
C A thin flat sheet as generally observed
D A solid square block in typical laboratory settings
A wire of cross-section 1 mm<sup>2</sup> and Young's modulus 2×10<sup>11</sup> Pa is stretched to a longitudinal strain of 0.05%. The force applied is:
A rod (Y = 2×10<sup>11</sup> Pa, α = 1.2×10<sup>-5</sup> /K) is clamped rigidly between two walls and heated through 50 K. The thermal stress developed is:
A wire of given material and radius can support a maximum load W before breaking. A wire of the same material and radius but twice the length can support a maximum load of:
A steel wire (Y = 2×10<sup>11</sup> Pa) and a copper wire (Y = 1×10<sup>11</sup> Pa) of equal length and cross-section are joined end to end and stretched by the same force. The ratio of their elongations (steel : copper) is:
A metal cube of side 0.1 m has a tangential force of 100 N applied to its top face. If the shear modulus is 2.5×10<sup>10</sup> Pa, the lateral displacement of the top face is:
Two wires A and B of the same material and same length, but radius of A is twice that of B, are stretched by the same force. The ratio of elastic potential energy stored in A to that in B is:
A composite rod is made of two equal-length segments, one of Youngs modulus Y1 and area A, and the other of Youngs modulus Y2 and the same area A, joined end to end and stretched by force F. The effective Youngs modulus of the composite rod is:
A spherical ball of volume V made of a material with bulk modulus B is dropped into a lake to depth h. The fractional decrease in volume (ΔV/V) at that depth (ignoring atmospheric pressure) is approximately:
A metal wire of Youngs modulus Y is stretched by a load such that the strain is x. If the load is increased so the strain doubles (still within elastic limit), how does the elastic energy stored per unit volume change?
A rod fixed between two rigid walls is heated so that it would expand by ΔL if free, but the walls prevent any expansion. If Youngs modulus is Y, area A, and coefficient of linear expansion is α, the thermal stress (compressive force per area) developed is:
A wire is replaced by another wire of the same material but with half the diameter, used to support the same load, suspended for the same length. Compared to the original, the new wire is:
A Equally safe, since the cross-sectional area change has no effect on stress
B Four times more likely to cross its elastic limit due to higher stress
C Safer because the thinner wire stretches less under the same load
D Unaffected since strain depends only on the material, not the geometry
A cube of side a is subjected to three mutually perpendicular equal stresses sigma on its faces (hydrostatic compression). If Youngs modulus is Y and Poissons ratio is sigma_p, the fractional decrease in volume in terms of bulk modulus B is given by ΔV/V = 3σ/Y multiplied by a factor. That factor, expressed using Poissons ratio, is:
A weight stretches a wire by 1 mm. A second wire of the same material but double the length and double the radius carries the same weight. Its elongation is:
A rod is rigidly clamped between two fixed walls and its temperature is raised by ΔT. The thermal stress developed (Y = Young modulus, α = expansion coefficient) is: