Tuesday, 12 February 2019

Simple Stress & Strain


01. The stress at a point is a
(a) Vector 
(b) Scalar
(c)Tensor 
(d)None

02. A ‘strut’ is  a member, which is  primarily subjected to
(a) Axial compression
(b) Axial tension
(c) Flexural  compression 
(d) Flexural tension

03. “Shear Strain” is defined as
(a) Rate of change of angle
(b) Change in angle between two planes
(c) Change in angle between planes at right angles
(d) Distortion of fibers

04. The property of material by which it can be beaten (or) rolled into plate is called
(a) Malleability  
(b) Plasticity
(c) Ductility 
(d) Elasticity

05. Which of the following is the nominal stress-strain curve for mild steel


06. The stress based on actual area of cross section during tension stage of a mild steel specimen is called
(a) Nominal stress
(b) Normal stress
(c) True stress 
(d) Yield stress

07. Which of the following is considered as  a  true characteristic  yield stress for mild steel
(a) Proof stress 
(b) Ultimate stress
(c) Upper yield point 
(d) Lower yield point

08. For mild steel the lower yield points more significant than upper yield point because
(a) Strain is more at this point
(b) It is less than upper yield point
(c) It is less affected by shape of the section
(d) None of the above

09. The “Gauge length “to be used for conduction a tension generally function of
(a) Diameter bar 
(b) Length of bar
(c) both (a) & (b) 
(d) None of the above

10. Factor of safety for a ductile material is the ratio of
(a) Ultimate stress to yield stress
(b) Ultimate stress to working stress
(c) Breaking stress to working stress
(d) Yield stress to working stress

11. Variation of strain of a material at constant stress is :
(a) Relaxation
(b) Creep
(c) Shrinkage 
(d) Hysteresis

12. The ability of material to absorb a large amount of energy is:
(a) Ductility 
(b) Hardness
(c) Toughness 
(d) Resilience

13. A material which undergoes no deformation till its yield point is reached and then it flow at a constant stress is:
(a) Elastic - plastic 
(b) Rigid - Plastic
(c) Non - plastic 
(d) Non - plastic

14. For metals which do not have a well-defined yield point, the proof stress is determined by drawing a line parallel to the initial tangent at an offset of m:
(a) 0.2 percent 
(b) 0.5 percent
(c) 1.0 percent 
(d) 2.0 percent

15. Leuder’s lines on steel specimen under simple tension test is a direct indication of yielding of material due to slip along the plane.
(a) of maximum principal stress
(b) of maximum shear stress
(c) of loading
(d) perpendicular to the direction of loading

16. When a mild-steel specimen fails in a tension- test, the fracture looks like


17. As soon as the external forces causing deformation in a perfectly elastic body are withdrawn, the elastic deformation disappears
(a) only partially
(b) completely over a prolonged period of time
(c) completely and instantaneously
(d) completely after an initial period of rest

18. For engineering materials, Poisson’s ratio lies between
(a) 0 and 1 
(b) -1 and +1
(c) -1/2 and + 1/2 
(d) 0 and 1/2

19. In a compression test on mild steel
(a) necking does not occur
(b) Hooke’s law is not valid
(c) Hooke’s law is valid beyond yield point
(d) ultimate stress is more than failure stress

20. For most brittle materials generally ultimate strength in compression is much larger than the ultimate strength in tension because
(a) of flaws such as microscopic cracks or cavities
(b) compression failure is due to normal stress and failure in tension is due to shear stress
(c) yield point does not occur in compression
(d) of inherent properties of materials

21. Which of the following is primarily responsible for toughness of steel?
(a) Iron
(b) Carbon
(c) Manganese
(d) Phosphorous

22. The modulus of elasticity of high tensile steel is
(a) smaller than that of mild steel
(b) equal to that of mild steel
(c) larger than that of mild steel
(d) equal to that of aluminium

23. The stress-strain curve for an ideally plastic material is


24. One of the following favors brittle fracture in a ductile material?
(a) Elevated temperature
(b) Slow rate of straining
(c) Presence of notch
(d) Circular cross - section

01. The independent number of elastic constants for a completely an isotropic elastic material following Hook’s law, is ______

02. For non-dilatant material, the maximum value of Poisson’s ratio is …….

03. The shear modulus of most materials with respect to the module of elasticity is
(a) More than half 
(b) Less than half
(c) Equal to half 
(d) Unrelated

04. A given material has Young’s modulus E, modulus of rigidity and Poisson’s ratio 0.25. The ratio of Young’s modulus to modulus of rigidity of this material is _________

05. In an experiment it is found that the bulk modulus of a material  is equal to its shear modulus. The Poisson’s ratio is _________

06. The ratio of Young’s modulus to modulus of rigidity for a material having Poisson’s ratio 0.2 is
(a) 12/5 
(b) 5/12 
(c)5/14 
(d)14/5

07. The material of a rubber balloon has a Poisson’s ratio of 0.5. If uniform pressure is applied to blow the balloon, the volumetric strain of the material will be
(a) 0.50 
(b) 0.25 
(c) 0.20 
(d) zero
08. The relation between the three elastic constants is
(a) E=3KC / (K+C) 
(b) 6KC / (3K+C)
(c) E = 9KC / (3K+C)  
(d) E = 3KC / (3K+C)

09. For any structural material, the value of Poisson’s ratio is always
(a) greater than 1
(b) between 0.5 and 1.0
(c) between ‘0’ and '0.5'
(d) between ‘0’ and ‘0.05’ 

10. For structural steel, the relative magnitudes of three modulii of elasticity E, C and K is given by
(a) E>C>K 
(b) K>C>E
(c) C<K<E 
(d)C>E>K

11. The ratio of bulk modulus to Young’s modulus is about:
(a) Less than half
(b) Less than one third
(c) More than one third
(d) No relation at all

12. In terms of Poisson’s ratio (y) the ratio of Young’s Modulus (E) to Shear Modulus(G) of elastic materials is
(a) 2(1 +v) 
(b) 2(1-v)
(c) 1/2 (1+v) 
(d) 1/2 (l-v)

13. A circular rod of 10 mm diameter is tested for tension and it was observed that when tension was 11 kN, the total extension on a 300 mm length was 0.20 mm. Young’s modulus is
(a) 210 kN / mm3 
(b) 210 kN / mm2
(c) 140.06 kN / mm3
(d) None

14. If the modulus of rigidity is 80 kN/mm2 and bulk modulus is 140 kN / mm2 Poisson’s ratio is
(a) 0.2 
(b) 0.25 
(c) 0.26 
(d) 0.33

15. Match the following using the codes given below:

Type of material
A. Concrete 
B. Cork
C. Rubber 
D. Isotropic Materials
General value of Poisson’s ratio
1.   0  
2.   0.15
3.   0.25  
4.   0.33  
5.   0.5
Codes:
      A B C D 
(a) 2 1 5 4 
(b) 2 1 5 3
(c) 3 1 5 4 
(d) 3 5 1 4

16. If, for a given material, E = 2G (E is modulus of elasticity and G is modulus of rigidity of the material), then the bulk modulus ‘K’ will be
(a) E / 3 
(b) E / 2 
(c) E / 4 
(d) E

17. Given that for an element in a body of homogeneous isotropic material subjected to plane stresses , εx,εy and εz are normal strains in x, y and z directions respectively and μ is the Poisson’s ratio, the magnitude of unit volume charge of the element is given by
(a) εxεyεz
(b) εx-μ (εyεz)
(c) μ(εx + εy + εz)
(d) (1 /εx ) + (1 /εy  + (1 /εz )

18. A steel cube of volume 8000 cc is subjected to all round stress of 1330 kg/cm2. The bulk modulus of the material is 1.33 x 106 kg/cm2. The volumetric change is
(a) 8 cc 
(b) 6 cc
(c) 0.8 cc  
(d) 10-3 cc

01. A square bar of certain material with 4 cm side, is subjected to a pull of 16t, where by the extension is 0.1 cm in a length of 200 cm. If the Poisson’s ratio is 1/ 4, the rigidity modulus of the material in kg / cm2
(a) 2 x 10
(b) 1.6 x 106
(c) 1.8 x 10
(d) 0.8 x 106

02. A bar 4 cm in diameter is subjected to an axial load of 4 t. The extension of the bar over a gauge length of 20 cm is 0.03 cm. The decrease in diameter is 0.0018 cm. The Poisson’s ratio is
(a) 0.25 
(b) 0.30
(c) 0.33 
(d) 0.35

03. A steel rod of circular section tapers from 2 cm diameter to 1 cm diameter over a length of 50cm. If the modulus of elasticity of the material is 2 x 106 kg/cm2, then the increase in length under a pull of 3000 kg will be
(a) 0.3/2 πcm 
(b) 30/πcm
(c)300/π
(d) 750 cm 

04. A cylindrical bar of 20 mm diameter and 1 m length is subjected to a tensile test. Its longitudinal strain is 4 times that of its lateral strain. If the modulus of elasticity is 2 x 1 0 N /mm2, then its modulus of rigidity will be
(a) 8 x 106 N /mm2 
(b) 8 x 105 N /mm2
(c) 0.8 x 104  N /mm2
(d) 0.8 x 105N /mm2

05. An short cast iron column carries a load of 50 t. If the original  and Poisson’s ratio = 0.25, the increase in dia of
column in ‘cm’ would be
(a) 0.003 18 
(b) 0.00256
(c) 0.002 
(d) 0.00280

06. A spherical ball of volume 20m3 is placed under a certain liquid where in the ball is subjected to a uniform hydrostatic pressure of 200 MPa. If the material of the ball has a bulk modulus of elasticity of 2.5 x 105 MPa and a Poisson’s ratio of 0.30, then due to the hydrostatic pressure, the volume of the ball will change by
(a) 0.0008 m3 
(b) 0.0 144 m3
(c) 0.0160 m3 
(d) 0.048 m3

01. A steel rod of 2 cm2 area and 1 m in height is subjected to a pull of 40,000 N. If Young’s Modulus is 2 x 1 0 N/mm2, the elongation of the rod in mm will be
(a) 10 
(b) 100 
(c) 1 
(d) 0.1

02. A steel rod of length 1m extends by 1 mm when subjected to an axial load in N/mm2, the stress developed is
(a) 50 
(b) 100 
(c) 200 
(d) 400

03. The diameter of a tapering rod varies from ‘D’ to ‘D/2’ in length of ‘L’ m. If it is subjected to an axial tension of ‘P’ the change in length is
(a) 4 PL / μ ED2 
(b) 8 PL / μ ED2
(c)2 PL/μ ED2
(d) None

04. An elastic bar of length ‘l’ area of cross section ‘A’ self weight ‘W’ is hanging vertically. It is subjected to an axial comp.load of ‘W’ units at the bottom end. The change in length of bar is:
(a) WL / 2 AE (Extension)
(b) WL / 2 AE (contraction)
(c) 3 WL / 2 AE (Extension)
(d) WL / AE (contraction)

05. The elongation of the bar due to its own weight is
(a)Wl/2AE
(b)Wl/AE 
(c) WI/b2E
(d)2W/AE

06. If all the dimensions of a vertically suspended circular bar are doubled, then the maximum stress produced in it due to its own weight will
(a) become half
(b) remain unaltered
(c) be doubled
(d) be tripled

07. If all the dimensions of a vertically suspended circular bar are doubled and cross sectional area is made half, then the maximum change length due to its own weight will
(a) become half
(b) remain unaltered
(c) be doubled 
(d) be four times

08. A plate of 1 cm thick and 5 cm wide has a rivet hole of diameter 1 cm as shown in figure. It is subjected to a load of 1000 N. the maximum tensile stress. In the plate is approximately .........MPa

09. Two bars of same size but of different materials are subjected to same tensile force. If the bars have their axial elongation in the ratio of 4 : 6, then the ratio of modulus of elasticity of the two materials would be___

01. The axial movement of bottom surface of compound bar loaded as shown below is

(a) 1.5 (PL/AE)
(b) 2.0 (PL/AE) 2A LE
(e) 2.5 (PL/AE) ‘
(d) 3.0 (PL/AE)

02. ABC is rigid bar. It is hinged at ‘A’ and suspended at ‘B’ and ‘C’ by two wires ‘BD’ arid ‘CE’ made of copper and steel respectively. The bar carries a load of 1 t at ‘F’ midway between ‘B’ and ‘C’.
Given A = 4 cm2 = 2 cm2 E=1x106kg/cm2 Es=2x10 6kg/cm2
The ratio of forces in copper and steel wires is,

(a) 0.5 
(b) 4
(c) 0.25
(d) 2

03. The ratio of loads shared by parts ‘AB’ and ‘BC’ of the bar shown below is

(a) 1:1
(b) 2:1
(c) 3:1
(d) 1:2

04. An elastic body is subjected to a direct compressive stress ‘Px' in longitudinal direction. If the lateral strains in the other two directions are prevented by applying ‘Py’ and ‘Pz’ in those
directions, then Py= Pz is equal to (‘’ Poisson’sratio)
(a) Px / (μ - 1) 
(b) μ.  Px
(c)Pxμ(1- 2) 
(d)μ . Px/ (1 - μ)

05. A hole to be punched in a plate of 10 mm thick. The allowable crushing stress of the punch is 4 times the shearing / stress of the plate. diameter of the smallest hole that can be punched in the plate in ‘mm’ is
(a) 10mm 
(b) 20mm
(c) 40 mm 
(d) none

06. For the cantilever beam as shown in Figure the cross-sectional area of the steel, aluminum and bronze part is 500 mm2, 400 mm2 and 200 mm2 respectively. The maximum P that will not exceed a stress  in steel of 140 MPa, in Aluminum of 90 Mpa or in Bronze of 100 MPa Is


(a) 25000 N
(b) 36030 N
(c) 14000 N
(d) 10000 N

07. Assume that Young’s modulus of steel is twice that of brass. Two bars of brass and a bar of steel of equal cross — section form a single tension member with the help of rigid pins as shown in the figure. The shear in the pin will be

(a)0.25P
(b)0.5P
(c)0.33P 
(d)0.4P

08. A rigid beam LI3CD is hinged at D and supported by two springs at A and B as shown in the figure. The beam carries a vertical load P at C. The stiffness of spring at A is 2K and that of B is K. The ratio of forces of spring at A and that of spring at B is

(a) 1
(b) 2
(c) 3
(d) 4

01.f a steel tyre is heated and struck on a rigid wheel, after cooling the tyre will be subjected to
(a) Normal compression
(b) Normal tension
(c) Hoop compression
(d) Hoop tension

02. A steel bar is kept between two copper(parallel) bars and rigidly connected at room temperature together. system cooled suddenly, the stresses produced in the bars will be
(a) tension in steel & compression in copper
(b) compression in both steel & copper
(c) tension in both steel & copper
(d) compression m steel & tension in copper

03. A square plate (a x a) rigidly held at three edges is free to move along the fourth edge. If temperature of the plate is raised by temperature ‘t’, then the free expansion at the fourth edge
will be (coefficient of thermal expansion of the material is a , modulus of elasticity of the material is E and its Poisson’s ratio is μ
(a) a α t μ
(b)a α t(1+μ)
(c)a α t + α t μ 
(d)a α t(1-μ)

04 A thin steel tyre of diameter ‘d’ is to be shrunk on to slightly large wheel of diameter ‘D’ , if E is the modulus of elasticity of steel, the circumferential stress developed is
(a) ((D-d) / d ) E comp
(b) ((D-d) / d) E tensile
(c) ((D-d) / D) E comp
(d) ((D-d) / D) E tensile

05. A composite bar of steel and copper as shown in fig. i.e., subjected to Copper rise of temperature, the steel bar will be under ( αc   αs)

(a) Tension 
(b) Compression
(c) Shear 
(d) No stress

06. A uniform, slender cylindrical rod is made of a homogeneous and isotropic material. The rod rests on a frictionless surface. The rod is heated uniformly. The radial and longitudinal thermal
stresses are represented by Gr and az respectively
(a) σr = 0; σz =0
(b)σr = 0; σz ≠ 0
(c) σr ≠ 0; σz = 0
(d)σr ≠ 0; σz ≠ 0

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