Strength of Materials 1000+ MCQ with answer for XAT

1. Percentage reduction in area performing tensile test on cast iron may be of the order of
A. 50 %
B. 25 %
C. 20 %
D. 30 %
Answer : C

2. The total strain energy stored in a body is termed a
A. Resilience
B. Proof resilience
C. Modulus of resilience
D. Toughness
Answer : A

3. The ratio of direct stress to volumetric strain in case of a body subjected to three mutually perpendicular stresses of equal intensity, is equal to
A. Young's modulus
B. Bulk modulus
C. Modulus of rigidity
D. Modulus of elasticity
Answer : B

4. Which of the following has the minimum atomic mass?
A. Oxygen
B. Sulphur
C. Nitrogen
D. Carbon
Answer : D

5. When coal is first dried and then crushed to a fine powder by pulverising machine, the resulting fuel is called
A. Wood charcoal
B. Bituminous coal
C. Briquetted coal
D. None of these
Answer : D

6. The heat and work are mutually convertible. This statement is called __________ law of thermodynamics.
A. Zeroth
B. First
C. Second
D. Third
Answer : B

7. When a body is subjected to two equal and opposite pushes, as a result of which the body tends to reduce its length, then
A. The stress and strain induced is compressive
B. The stress and strain induced is tensile
C. Both A and B is correct
D. None of these
Answer : A

8. Which of the following statement is correct according to Clausis statement of second law of thermodynamics?
A. It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature.
B. It is impossible to transfer heat from a body at a lower temperature to a body at a higher temperature, without the aid of an external source.
C. It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature by using refrigeration cycle.
D. None of the above
Answer : B

9. The efficiency of the Carnot cycle is (where T1 and T2 = Highest and lowest temperature during the cycle)
A. (T₁/T₂) - 1
B. 1 - (T₁/T₂)
C. 1 - (T₂/T₁)
D. 1 + (T₂/T₁)
Answer : C

10. Strain re-setters are used to
A. Measure shear strain
B. Measure linear strain
C. Measure volumetric strain
D. Relieve strain
Answer : B

11. When two plates are butt together and riveted with cover plates with two rows of rivets, the joint is known as
A. Lap joint
B. Butt joint
C. Single riveted single cover butt joint
D. Double riveted double cover butt joint
Answer : D

12. For the beam shown in the below figure, the shear force diagram between A and B is

A. A horizontal line
B. A vertical line
C. An inclined line
D. A parabolic curve
Answer : D

13. The stress induced in a body, when suddenly loaded, is ________ the stress induced when the same load is applied gradually.
A. Equal to
B. One-half
C. Twice
D. Four times
Answer : C

14. A boiler shell 200 cm diameter and plate thickness 1.5 cm is subjected to internal pressure of 1.5 MN/m, and then the hoop stress will be
A. 30 MN/m²
B. 50 MN/m²
C. 100 MN/m²
D. 200 MN/m²
Answer : C

15. The thermal efficiency of an ideal gas turbine plant is given by (where r = Pressure ratio)
A. r^? - 1
B. 1 - r^? - 1
C. 1 - (1/r) ^{?/? - 1}
D. 1 - (1/r) ^{? - 1/ ?}
Answer : D

16. The absolute zero temperature is taken as
A. -273°C
B. 73°C
C. 237°C
D. -237°C
Answer : A

17. A composite shaft consisting of two stepped portions having spring constants K? and K? is held between two rigid supports at the ends. Its equivalent spring constant is
A. K? K?
B. (K? + K?)/ 2
C. (K? + K?)/ K? K?
D. K? K?/ (K? + K?)
Answer : A

18. The ultimate tensile stress of mild steel compared to ultimate compressive stress is
A. Same
B. More
C. Less
D. Unpredictable
Answer : B

19. The expansion ratio (r) is the ratio of (where v1 = Volume at the beginning of expansion, and v2 = Volume at the end of expansion)
A. v₁/v₂
B. v₂/v₁
C. (v₁ + v₂)/v₁
D. (v₁ + v₂)/v₂
Answer : B

20. The buckling load for a given column depends upon
A. Area of cross-section of the column
B. Length and least radius of gyration of the column
C. Modulus of elasticity for the material of the column
D. All of the above
Answer : D

21. The bending moment at a point on a beam is the algebraic ________ of all the moments on either side of the point.
A. Sum
B. Difference
C. Multiplication
D. None of the above
Answer : A

22. The efficiency of the dual combustion cycle for the same compression ratio is __________ Diesel cycle.
A. Greater than
B. Less than
C. Equal to
D. None of these
Answer : A

23. The heat flows from a cold body to a hot body with the aid of an external source. This statement is given by
A. Kelvin
B. Joule
C. Clausis
D. Gay-Lussac
Answer : C

24. The pull required to tear off the plate per pitch length is (where p = Pitch of rivets, t = Thickness of plates, and ?t, ? and ?c = Permissible tensile, shearing and crushing stresses respectively)
A. (p - 2d) t × ?_c
B. (p - d) t × ?
C. (p - d) t × ?_t
D. (2p - d) t × ?_t
Answer : C

25. The buckling load for a given material depends on
A. Slenderness ratio and area of cross-section
B. Poisson's ratio and modulus of elasticity
C. Slenderness ratio and modulus of elasticity
D. Slenderness ratio, area of cross-section and modulus of elasticity
Answer : D

26. The cycle in which heat is supplied at constant volume and rejected at constant pressure is known as
A. Dual combustion cycle
B. Diesel cycle
C. Atkinson cycle
D. Rankine cycle
Answer : C

27. The mass of excess air supplied is equal to
A. (23/100) × Mass of excess carbon
B. (23/100) × Mass of excess oxygen
C. (100/23) × Mass of excess carbon
D. (100/23) × Mass of excess oxygen
Answer : D

28. One kg of carbon monoxide requires _______kg of oxygen to produce 11/7 kg of carbon dioxide gas.
A. 11/7
B. 9/7
C. 4/7
D. All of the above
Answer : C

29. The maximum tangential stress in a thick cylindrical shell is always _________ the internal pressure acting on the shell.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : C

30. In an irreversible process, there is a
A. Loss of heat
B. No loss of heat
C. Gain of heat
D. No gain of heat
Answer : A

31. The oxygen atom is ________ times heavier than the hydrogen atom.
A. 2
B. 8
C. 16
D. 32
Answer : C

32. Which of the following is the correct statement?
A. All the reversible engines have the same efficiency.
B. All the reversible and irreversible engines have the same efficiency.
C. Irreversible engines have maximum efficiency.
D. All engines are designed as reversible in order to obtain maximum efficiency.
Answer : C

33. The measurement of a thermodynamic property known as temperature is based on
A. Zeroth law of thermodynamics
B. First law of thermodynamics
C. Second law of thermodynamics
D. None of these
Answer : A

34. The value of 1 mm of Hg is equal to
A. 1.333 N/m²
B. 13.33 N/m²
C. 133.3 N/m²
D. 1333 N/m²
Answer : C

35. Tensile strength of a material is obtained by dividing the maximum load during the test by the
A. Area at the time of fracture
B. Original cross-sectional area
C. Average of (A) and (B)
D. Minimum area after fracture
Answer : B

36. Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle
A. Combustion is at constant volume
B. Expansion and compression are isentropic
C. Maximum temperature is higher
D. Heat rejection is lower
Answer : D

37. The ratio of molar specific heats for mono-atomic gas is
A. 1
B. 1.4
C. 1.67
D. 1.87
Answer : C

38. When a closely-coiled helical spring of mean diameter (D) is subjected to an axial load (W), the stiffness of the spring is given by
A. Cd?/D³n
B. Cd?/2D³n
C. Cd?/4D³n
D. Cd?/8D³n
Answer : D

39. The ratio of root mean square velocity to average velocity of gas molecules at a particular temperature is
A. 0.086
B. 1.086
C. 1.086
D. 4.086
Answer : B

40. The absolute zero pressure can be attained at a temperature of
A. 0°C
B. 273°C
C. 273 K
D. None of these
Answer : D

41. The point of contraflexure is a point where
A. Shear force changes sign
B. Bending moment changes sign
C. Shear force is maximum
D. Bending moment is maximum
Answer : B

42. Modulus of rigidity is defined as the ratio of
A. Longitudinal stress to longitudinal strain
B. Volumetric stress to volumetric strain
C. Lateral stress to Lateral strain
D. Shear stress to shear strain
Answer : D

43. Select the correct statement as per Charles' law
A. p.v = constant, if T is kept constant
B. v/T = constant, if p is kept constant
C. p/T = constant, if v is kept constant
D. T/p = constant, if v is kept constant
Answer : B

44. Which of the following is correct?
A. Gauge pressure = Absolute pressure + Atmospheric pressure
B. Absolute pressure = Gauge pressure + Atmospheric pressure
C. Absolute pressure = Gauge pressure - Atmospheric pressure
D. Atmospheric pressure = Absolute pressure + Gauge pressure
Answer : B

45. The value of gas constant (R) in S. I. units is
A. 0.287 J/kgK
B. 2.87 J/kgK
C. 28.7 J/kgK
D. 287 J/kgK
Answer : D

46. The stress induced in a body due to suddenly applied load compared to when it is applied gradually is
A. Same
B. Half
C. Two times
D. Four times
Answer : C

47. When the expansion or compression takes place according to the law pvn = C, the process is known as
A. Isothermal process
B. Adiabatic process
C. Hyperbolic process
D. Polytropic process
Answer : D

48. Carnot cycle has maximum efficiency for
A. Petrol engine
B. Diesel engine
C. Reversible engine
D. Irreversible engine
Answer : C

49. The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is always __________ one.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : C

50. In order to know whether a column is long or short, we must know its
A. Ultimate shear stress of the column
B. Factor of safety
C. Torque resisting capacity
D. Slenderness ratio
Answer : D