Mechanical Properties of Solids Mock Test – Class 11 Physics

1. A cylindrical wire is stretched, and its diameter decreases. If the diameter is used to find lateral strain, the correct expression and sign for stretching are

2. A circular wire is stretched by a force . Its radius is measured too high, while is measured correctly. The calculated stress will be approximately

3. The SI unit of shear modulus is

4. A passage describes a testing setup: a wire is first loaded within the straight part of its force-extension graph, then loaded beyond the elastic limit, and finally unloaded. The observation most consistent with this description is

5. A beam is bent downward by a load at its middle. A designer increases the depth of the beam while keeping much of the material near the top and bottom faces. The main reason this improves resistance to bending is that

6. In a stress-strain graph, Region is a straight line through the origin, Region is a curved but still recoverable part, Region leaves permanent strain after unloading, and Point is the highest stress reached. The best interpretation is

7. A solid is subjected to pressure in all directions, but a learner calls the stress “tensile” because the pressure is large. The better correction is that the stress is

8. Consider the statements below.
I. A high helps reduce extension under a given tensile stress.
II. A high helps reduce fractional volume change under pressure.
III. A high helps reduce shearing strain under a given shearing stress.
IV. A high compressibility means the material strongly resists volume change.
The suitable set is

9. A hollow cylindrical shaft and a solid shaft are made from the same material and have the same outer radius. In a qualitative design discussion, the hollow shaft is often preferred when saving material while resisting twisting is important because

10. A metal rod of length , area , , and is heated by . It is held so that only of its free expansion is prevented. The thermal stress and force exerted by the supports are

11. A long metal strip is free to expand on heating in one setup and is rigidly clamped at both ends in another setup. The clamped setup develops larger stress because

12. A block is sheared so that the sideways displacement of the top face is not small compared with the block height. The relation becomes questionable mainly because

13. A wire is stretched slowly and then unloaded along a different path on the force-extension graph. The loading area is , and the unloading area is . The energy lost in one cycle is

14. A wire of length and area is stretched by a load that produces elastic energy . If , the load and extension are closest to

15. A wire has longitudinal strain when stretched. If Poisson’s ratio of the material is , the lateral strain is

16. The following claims are made after a full elastic test of a wire.
I. The slope of the stress-strain graph gives Young’s modulus.
II. The area under the force-extension graph gives work done.
III. The area under the stress-strain graph gives elastic energy density.
IV. The slope of the force-extension graph is always equal to Young’s modulus.
The suitable set is

17. A solid of initial volume is compressed uniformly and its volume decreases by . Taking decrease in volume as negative, the volumetric strain is

18. A solid block of height and top-face area is sheared by a tangential force . If the material has shear modulus , the sideways displacement of the top face is

19. The dimensional formula of elastic modulus is the same as that of

20. A solid block is compressed uniformly and also tested in shear. In the compression test, , , and . In the shear test, and . The values of and are respectively

21. The SI unit and dimensional formula of bulk modulus are respectively

22. In the relation , if is close to while is finite, the value of must be very large. The physical meaning is that the material is

23. For the cable in the previous design idea, the material has breaking stress and the required factor of safety is . If the area is , the safe load by strength condition is

24. A cylindrical wire of diameter is stretched so that its longitudinal strain is . If , the change in diameter is

25. A stress-strain curve is described in this order: first a straight line from the origin, then a region where recovery is still possible but strict proportionality is lost, then yielding, then a maximum stress point, and finally fracture. The maximum stress point is best identified as

26. A wire of length , radius , and is stretched by . Taking , the elastic energy stored and energy density are closest to

27. The following data refer to wires of the same material stretched within the elastic limit.

If the extension of is , the extensions of and are respectively

28. A wire of radius carries a load of . Taking , the tensile stress is closest to

29. A wire has a straight load-extension graph with slope . Its length is and radius is . Taking , the Young’s modulus and the energy stored at extension are closest to

30. A wire of length , cross-sectional area , and extension is pulled by a force within its elastic limit. The expression for Young’s modulus is

31. In a material test, the following observations are made: the first part of the stress-strain graph is straight; after that the curve bends; still later, unloading leaves permanent strain. The sequence of ideas represented is

32. An isotropic material has and . Using , and then , the values of and are closest to

33. A solid has bulk modulus . Its compressibility is closest to

34. A wire of length , area , and is stretched by . The stress and extension are respectively

35. In a graph-based elastic test, the slope of the stress-strain graph is . A wire of the same material has and . The slope of its load-extension graph is

36. The same force is applied normally to two flat surfaces. Surface P has area , while surface Q has area . Compared with the stress on P, the stress on Q is

37. A wire is made longer without changing its material or cross-sectional area. In the ideal uniform-wire model, its breaking load is unchanged, but its extension under the same safe load increases. The best explanation is that

38. A stress-strain graph and a load-extension graph are drawn for the same wire within the elastic limit. The slope of the stress-strain graph gives , while the slope of the load-extension graph gives

39. Two wires are made of the same material and have the same length. Wire has cross-sectional area , while wire has cross-sectional area . If the material has the same breaking stress in both wires, the breaking load of is

40. A stress-strain curve of a metal is described as follows: the initial part is straight, unloading from a later curved part still gives full recovery, unloading from a still later part leaves a permanent set, and the highest point of stress occurs before final fracture. The correct interpretation is

41. A material shows a long nearly horizontal region on its stress-strain curve after the elastic part, and it can be drawn into a wire before fracture. This combination most strongly indicates

42. A table gives observations from three different materials tested under suitable elastic conditions.

The correct matching is

43. A composite cable has two segments in series. Segment has , , , and breaking stress . Segment has , , , and breaking stress . If the factor of safety is , the safe load and total extension at that load are

44. The following observations are recorded for three materials.

The best classification is

45. A rectangular block has height . Its top face is displaced sideways by while the lower face remains fixed. The shearing strain is

46. A wire of radius is stretched by a load of . The tensile stress in the wire is closest to

47. A stress-strain graph is drawn with stress on the vertical axis and strain on the horizontal axis. In the initial straight-line region, the slope of the graph represents

48. In a lab report, a wire of length and diameter is stretched by . A learner calculates stress using . The calculated stress will be

49. For a solid compressed uniformly by an increase in pressure , the bulk modulus is commonly written as . The negative sign is used because

50. A learner compares two wires under the same load and says, “The thicker wire stretches less only because it has less stress.” The most complete correction is that the thicker wire stretches less because