**Strength of Materials MCQ**

**SET-4**

**81. The ratio of change in volume to the original volume is called**

- A. linear strain
- B. lateral strain
- C. volumetric strain
- D. Poisson’s ratio

**Answer: C **

**82. In a beam where shear force changes sign, the bending moment will be**

- A. zero
- B. minimum
- C. maximum
- D. infinity

**Answer: C**

**83. The maximum shear stress of a beam of triangular section occurs above the neutral axis,**

- A. Correct
- B. Incorrect

**Answer: A**

**84. For the beam shown in the below figure, the shear force at A is equal to **

- A. wl/6
- B. wl/3
- C. wl
- D. 2 wl/3

**Answer: B**

**85. The ductility of a material __________ with the increase in percentage reduction in area of a specimen under tensile test.**

- A. increases
- B. decreases
- C. remains same

**Answer: A**

**86. The rivets are made from ductile material.**

- A. Yes
- B. No

**Answer: A**

**87. The rectangular beam ‘A’ has length l, width b and depth d. Another beam ‘B’ has the same length and width but depth is double that of ‘A’. The elastic strength of beam B will be __________ as compared to beam A.**

- A. same
- B. double
- C. four times
- D. six times

**Answer: C**

**88. When a closely-coiled helical spring is subjected to an axial load, it is said to be under**

- A. bending
- B. shear
- C. torsion
- D. crushing

**Answer: C**

**89. When a rectangular beam is loaded transversely, the zero stress is developed on the neutral axis.**

- A. True
- B. False

**Answer: A**

**90 ****. The given figure shows the Mohr’s circle of stress for two unequal and like principal stresses (σx and σy) acting at a body across two mutually perpendicular planes. The normal stress on an oblique section making an angle θ with the minor principle plane is given by**

- A. OC
- B. OP
- C. OQ
- D. PQ

**Answer: C**

**91. According to Euler’s column theory, the crippling load for a column of length (l) with one end fixed and the other end free is __________ the crippling load for a similar column hinged at both the ends.**

- A. equal to
- B. less than
- C. more than

**Answer: B**

**92. If percentage reduction in area of a certain specimen made of material ‘A’ under tensile test is 60% and the percentage reduction in area of a specimen with same dimensions made of material ‘B’ is 40%, then**

- A. the material A is more ductile than material B
- B. the material B is more ductile than material A
- C. the ductility of material A and B is equal
- D. the material A is brittle and material B is ductile

**Answer: A**

**93. 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**

**94. A body is subjected to two normal stresses 20 kN/m2 (tensile) and 10 kN/m2 (compressive) acting perpendicular to each other. The maximum shear stress is**

- A. 5 kN/m2
- B. 10 kN/m2
- C. 15 kN/m2
- D. 20 kN/m2

**Answer: C**

**95. When a cantilever beam is loaded at its free end, the maximum compressive stress shall develop at**

- A. bottom fibre
- B. top fibre
- C. neutral axis
- D. centre of gravity

**Answer: A**

**96. In a cantilever beam of length l subjected to a uniformly distributed load of w per unit length, the maximum deflection lies at the fixed end.**

- A. Yes
- B. No

**Answer: B**

**97. A lap joint is always in __________ shear.**

- A. single
- B. double

**Answer: A**

**98. The elongation of a conical bar under its own weight is __________ that of prismatic bar of the same length.**

- A. equal to
- B. half
- C. one-third
- D. two-third

**Answer: C**

**99. When the shear force diagram is a parabolic curve between two points, it indicates that there is a**

- A. point load at the two points
- B. no loading between the two points
- C. uniformly distributed load between the two points
- D. uniformly varying load between the two points

**Answer: D**

**100. The efficiency of a riveted joint is the ratio of the strength of the joint to the strength of the solid plate.**

- A. True
- B. False

**Answer: A**