Strength of Materials MCQ Solved Paper for UPSC CSE

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

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

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

4. The sum of internal energy (U) and the product of pressure and volume (p.v) is known as
A. Workdone
B. Entropy
C. Enthalpy
D. None of these
Answer : C

5. If the radius of wire stretched by a load is doubled, then its Youngs modulus will be
A. Doubled
B. Halved
C. Becomes four times
D. None of the above
Answer : D

6. According to Avogadro's law
A. The product of the gas constant and the molecular mass of an ideal gas is constant
B. The sum of partial pressure of the mixture of two gases is sum of the two
C. Equal volumes of all gases, at the same temperature and pressure, contain equal number of molecules
D. All of the above
Answer : C

7. If Kh is the torque resisting capacity of a hollow shaft and Ks is that of a solid shaft, of the same material, length and weight. Then,
A. Kh > Ks
B. Kh < Ks
C. Kh = Ks
D. None of these
Answer : A

8. Which of the following cycles is not a reversible cycle?
A. Carnot
B. Ericsson
C. Stirling
D. None of the above
Answer : D

9. Second law of thermodynamics defines
A. Heat
B. Work
C. Internal energy
D. Entropy
Answer : D

10. 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

11. For same compression ratio and for same heat added
A. Otto cycle is more efficient than Diesel cycle
B. Diesel cycle is more efficient than Otto cycle
C. Efficiency depends on other factors
D. Both Otto and Diesel cycles are equally efficient
Answer : A

12. Which of the following statement is correct?
A. The increase in entropy is obtained from a given quantity of heat at a low temperature.
B. The change in entropy may be regarded as a measure of the rate of the availability or unavailability of heat for transformation into work.
C. The entropy represents the maximum amount of work obtainable per degree drop in temperature.
D. All of the above
Answer : D

13. When the gas is heated at constant volume, the heat supplied
A. Increases the internal energy of the gas and increases the temperature of the gas
B. Does some external work during expansion
C. Both (A) and (B)
D. None of these
Answer : A

14. The general law for the expansion or compression of gases, is
A. pv = C
B. pv = m R T
C. pvⁿ = C
D. pv^? = C
Answer : C

15. Hooke's law holds good up to
A. Yield point
B. Limit of proportionality
C. Breaking point
D. Elastic limit
Answer : B

16. 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

17. Within elastic limit, stress is
A. Inversely proportional to strain
B. Directly proportional to strain
C. Square root of strain
D. Equal to strain
Answer : B

18. The pull required to crush the rivet per pitch length is
A. p.t.?_t
B. d.t.?_c
C. ?/4 × d² × ?_t
D. ?/4 × d² × ?_c
Answer : B

19. The amount of heat required to raise the temperature of __________ water through one degree is called kilojoules.
A. 1 g
B. 10 g
C. 100 g
D. 1000 g
Answer : D

20. The increase in entropy of a system represents
A. Increase in availability of energy
B. Increase in temperature
C. Decrease in pressure
D. Degradation of energy
Answer : D

21. A shaft revolving at ? rad/s transmits torque (T) in Nm. The power developed is
A. T.? watts
B. 2?. T.? watts
C. 2?. T.?/75 watts
D. 2?. T.?/4500 watts
Answer : A

22. The property of a material by irtue of which a body returns to its original, shape after removal of the load is called
A. Plasticity
B. Elasticity
C. Ductility
D. Malleability
Answer : B

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

24. A column of length (l) with both ends fixed may be considered as equivalent to a column of length __________ with both ends hinged.
A. l/8
B. l/4
C. l/2
D. l
Answer : C

25. When a body is subjected to a direct tensile stress (?) in one plane, then maximum normal stress occurs at a section inclined at __________ to the normal of the section.
A. 0°
B. 30°
C. 45°
D. 90°
Answer : A

26. The shape of cantilever for uniformly distributed load will be
A. Straight line
B. Parabolic
C. Elliptical
D. Cubic
Answer : B

27. 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

28. In open cycle gas turbine plants
A. The indirect heat exchanger and cooler is avoided
B. Direct combustion system is used
C. A condenser is used
D. All of the above
Answer : D

29. The assumption made in Euler's column theory is that
A. The failure of column occurs due to buckling alone
B. The length of column is very large as compared to its cross-sectional dimensions
C. The column material obeys Hooke's law
D. All of the above
Answer : D

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

31. The specific heat of water is
A. 1.817
B. 2512
C. 4.187
D. None of these
Answer : C

32. For the same maximum pressure and temperature,
A. Otto cycle is more efficient than Diesel cycle
B. Diesel cycle is more efficient than Otto cycle
C. Dual cycle is more efficient than Otto and Diesel cycles
D. Dual cycle is less efficient than Otto and Diesel cycles
Answer : B

33. The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight
A. Of same magnitude as that of bar and applied at the lower end
B. Half the weight of bar applied at lower end
C. Half of the square of weight of bar applied at lower end
D. One fourth of weight of bar applied at lower end
Answer : B

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

35. If in the equation pvn = C, the value of n = ?, then the process is called
A. Constant volume process
B. Adiabatic process
C. Constant pressure process
D. Isothermal process
Answer : A

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

37. A molecule consisting of one atom is known as
A. Mono-atomic
B. Di-atomic
C. Tri-atomic
D. Poly-atomic
Answer : A

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

39. When coal is strongly heated continuously for 42 to 48 hours in the absence of air in a closed vessel, the process is known as __________ of fuel.
A. Atomisation
B. Carbonisation
C. Combustion
D. None of these
Answer : B

40. A pressure vessel is said to be a thick shell, when
A. It is made of thick sheets
B. The internal pressure is very high
C. The ratio of wall thickness of the vessel to its diameter is less than 1/10.
D. The ratio of wall thickness of the vessel to its diameter is greater than 1/10.
Answer : D

41. One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to
A. 800 K
B. 1000 K
C. 1200 K
D. 1400 K
Answer : A

42. The shear force at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per metre at the centre, is
A. Zero
B. wl/4
C. wl/2
D. wl²/2
Answer : A

43. A vertical column has two moments of inertia (i.e. Ixx and Iyy ). The column will tend to buckle in the direction of the
A. Axis of load
B. Perpendicular to the axis of load
C. Maximum moment of inertia
D. Minimum moment of inertia
Answer : D

44. When a perfect gas is expanded through an aperture of minute dimensions, the process is known as
A. Isothermal process
B. Adiabatic process
C. Free expansion process
D. Throttling process
Answer : D

45. 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

46. 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

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

48. In case of an under-reinforced beam, the depth of actual neutral axis is __________ that of the critical neutral axis.
A. Same as
B. Less than
C. Greater than
D. None of these
Answer : B

49. The rivets are used for __________ fastenings.
A. Permanent
B. Temporary
C. Semi-permanent
D. None of these
Answer : A

50. When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is called
A. Zeroth law of thermodynamics
B. First law of thermodynamics
C. Second law of thermodynamics
D. Kelvin Planck's law
Answer : A