1000+ Strength of Materials Multiple Choice Question Answer [Solved]

1. Producer gas is obtained by
A. Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
B. Carbonisation of bituminous coal
C. Passing steam over incandescent coke
D. Passing air and a large amount of steam over waste coal at about 650°C
Answer : A

2. The shear force diagram for a simply supported beam carrying a uniformly distributed load of w per unit length, consists of
A. One right angled triangle
B. Two right angled triangles
C. One equilateral triangle
D. Two equilateral triangles
Answer : B

3. The moment of resistance of a balanced reinforced concrete beam is based on the stresses in
A. Steel only
B. Concrete only
C. Steel and concrete both
D. None of these
Answer : C

4. Stirling and Ericsson cycles are
A. Reversible cycles
B. Irreversible cycles
C. Semi-reversible cycles
D. Quasi-static cycles
Answer : A

5. A process of heating crude oil to a high temperature under a very high pressure to increase the yield of lighter distillates, is known as
A. Cracking
B. Carbonisation
C. Fractional distillation
D. Full distillation
Answer : A

6. The specific heat at constant volume is
A. The amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure
B. The amount of heat required to raise the temperature of unit mass of gas through one degree, at constant volume
C. The amount of heat required to raise the temperature of 1 kg of water through one degree
D. Any one of the above
Answer : B

7. The heat absorbed or rejected by the working substance is given by (where ds = Increase or decrease of entropy, T = Absolute temperature, and dQ = Heat absorbed or rejected)
A. ?Q = T.ds
B. ?Q = T/ds
C. dQ = ds/T
D. None of these
Answer : A

8. When a thin cylindrical shell is subjected to an internal pressure, the volumetric strain is (where ?? = Hoop strain, and ?? = Longitudinal strain)
A. 2?? - ??
B. 2?? + ??
C. 2?? - ??
D. 2?? + ??
Answer : B

9. The extension of a circular bar tapering uniformly from diameter d? at one end to diameter d? at the other end and subjected to an axial pull of P is given by
A. ?l = 4PE/ ?l²
B. ?l = 4?ld²/PE
C. ?l = 4Pl/?Ed?d?
D. ?l = 4PlE/ ?d?d?
Answer : C

10. The reading of the pressure gauge fitted on a vessel is 25 bar. The atmospheric pressure is 1.03 bar and the value of 'g' is 9.81 m/s2. The absolute pressure in the vessel is
A. 23.97 bar
B. 25 bar
C. 26.03 bar
D. 34.81 bar
Answer : C

11. According to Kelvin-Planck's statement, a perpetual motion of the __________ is impossible.
A. First kind
B. Second kind
C. Third kind
D. None of these
Answer : B

12. 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

13. Charles' law states that all perfect gases change in volume by __________ of its original volume at 0°C for every 1°C change in temperature, when pressure remains constant.
A. 1/27th
B. 1/93th
C. 1/173th
D. 1/273th
Answer : D

14. Stirling cycle consists of
A. Two constant volume and two isentropic processes
B. Two constant volume and two isothermal processes
C. Two constant pressure and two isothermal processes
D. One constant volume, one constant pressure and two isentropic processes
Answer : B

15. The work ratio of a gas turbine plant is given by
A. (Net work output)/(Workdone by the turbine)
B. (Net work output)/(Heat supplied)
C. (Actual temperature drop)/(Isentropic temperature drop)
D. (Isentropic increase in temperature)/(Actual increase in temperature)
Answer : A

16. The gas constant (R) is equal to the __________ of two specific heats.
A. Sum
B. Difference
C. Product
D. Ratio
Answer : B

17. When it is indicated that a member is elastic, it means that when force is applied, it will
A. Not deform
B. Be safest
C. Stretch
D. Not stretch
Answer : C

18. The total energy of a molecule is shared equally by the various degrees of freedom possessed by it. This law is known as
A. Law of equipartition of energy
B. Law of conservation of energy
C. Law of degradation of energy
D. None of these
Answer : A

19. Carbonisation of coal consists of
A. Drying and crushing the coal to a fine powder
B. Moulding the finely ground coal under pressure with or without a binding material
C. Heating the wood with a limited supply of air to temperature not less than 280°C
D. None of the above
Answer : D

20. The property of a material which allows it o be drawn into a smaller section is called
A. Plasticity
B. Ductility
C. Elasticity
D. Malleability
Answer : B

21. If a material expands freely due to heating it will develop
A. Thermal stresses
B. Tensile stress
C. Bending
D. No stress
Answer : D

22. If the rivets in adjacent rows are staggered and the outermost row has only one rivets, the arrangement of the rivets is called
A. Chain riveting
B. Zigzag riveting
C. Diamond riveting
D. Crisscross riveting
Answer : C

23. When wood is heated with a limited supply of air to a temperature not less than 280°C, the resulting fuel is
A. Coke
B. Wood charcoal
C. Bituminous coal
D. Briquetted coal
Answer : B

24. The entropy __________ in an irreversible cyclic process.
A. Remains constant
B. Decreases
C. Increases
D. None of these
Answer : C

25. 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

26. 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

27. The root mean square velocity of the gas molecules is given by (where k = Boltzmann's constant, T = Absolute temperature, and m = Mass of one molecule of a gas)
A. ?(KT/m)
B. ?(2KT/m)
C. ?(3KT/m)
D. ?(5KT/m)
Answer : C

28. A column that fails due to direct stress, is called
A. Short column
B. Long column
C. Weak column
D. Medium column
Answer : A

29. 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

30. Which of the following is the correct statement?
A. For a given compression ratio, both Otto and Diesel cycles have the same efficiency.
B. For a given compression ratio, Otto cycle is more efficient than Diesel cycle.
C. For a given compression ratio, Diesel cycle is more efficient than Otto cycle.
D. The efficiency of Otto or Diesel cycle has nothing to do with compression ratio.
Answer : B

31. The stress at which extension of the material takes place more quickly as compared to the increase in load is called
A. Elastic point of the material
B. Plastic point of the material
C. Breaking point of the material
D. Yielding point of the material
Answer : D

32. The volumetric or molar specific heat at constant pressure is the product of
A. Molecular mass of the gas and the specific heat at constant volume
B. Atomic mass of the gas and the gas constant
C. Molecular mass of the gas and the gas constant
D. None of the above
Answer : D

33. In an isothermal process,
A. There is no change in temperature
B. There is no change in enthalpy
C. There is no change in internal energy
D. All of these
Answer : D

34. The section modulus of a circular section about an axis through its C.G., is
A. ?d²/4
B. ?d²/16
C. ?d³/16
D. ?d³/32
Answer : D

35. Shear stress induced in a shaft subjected to tension will be
A. Maximum at periphery and zero at center
B. Maximum at center
C. Uniform throughout
D. None of the above
Answer : D

36. When a body is subjected to a direct tensile stress (?x) in one plane accompanied by a simple shear stress (?xy), the maximum normal stress i
A. (?x/2) + (1/2) × ?(?x² + 4 ?²xy)
B. (?x/2) - (1/2) × ?(?x² + 4 ?²xy)
C. (?x/2) + (1/2) × ?(?x² - 4 ?²xy)
D. (1/2) × ?(?x² + 4 ?²xy)
Answer : A

37. The heat supplied to the gas at constant volume is (where m = Mass of gas, c_v = Specific heat at constant volume, c_p = Specific heat at constant pressure, T₂ - T₁ = Rise in temperature, and R = Gas constant)
A. mR (T₂ - T₁)
B. mc_v (T₂ - T₁)
C. mc_p (T₂ - T₁)
D. mc_p (T₂ + T₁)
Answer : B

38. The property of a working substance which increases or decreases as the heat is supplied or removed in a reversible manner, is known as
A. Enthalpy
B. Internal energy
C. Entropy
D. External energy
Answer : C

39. 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

40. 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

41. A closely-coiled helical spring is cut into two halves. The stiffness of the resulting spring will be
A. Same
B. Double
C. Half
D. One-fourth
Answer : B

42. The heating of gas at constant volume is governed by
A. Boyle's law
B. Charles' law
C. Gay-Lussac law
D. Avogadro's law
Answer : C

43. In compression test, the fracture in cast iron specimen would occur along
A. The axis of load
B. An oblique plane
C. At right angles to the axis of specimen
D. Would not occur
Answer : B

44. The efficiency of the Carnot cycle may be increased by
A. Increasing the highest temperature
B. Decreasing the highest temperature
C. Increasing the lowest temperature
D. Keeping the lowest temperature constant
Answer : A

45. Which of the following materials is most elastic?
A. Rubber
B. Plastic
C. Brass
D. Steel
Answer : D

46. The unit of Young's modulus is
A. mm/mm
B. kg/cm
C. Kg
D. kg/cm²
Answer : D

47. A cube subjected to three mutually perpendicular stress of equal intensity p expenses a volumetric strain
A. 3p/E × (2/m - 1)
B. 3p/E × (2 - m)
C. 3p/E × (1 - 2/m)
D. E/3p × (2/m - 1)
Answer : C

48. Steam coal is a
A. Pulverised coal
B. Brown coal
C. Coking bituminous coal
D. Non-coking bituminous coal
Answer : D

49. For the constant pressure and heat input, the air standard efficiency of gas power cycle is in the order
A. Dual cycle, Diesel cycle, Otto cycle
B. Otto cycle, Diesel cycle, Dual cycle
C. Dual cycle, Otto cycle, Diesel cycle
D. Diesel cycle, Otto cycle, Dual cycle
Answer : A

50. The efficiency of Diesel cycle with decrease in cut-off
A. Increases
B. Decreases
C. First increases and then decreases
D. First decreases and then increases
Answer : A