**Strength of Materials Questions Answers (SoM) – Civil Engineering MCQ**

**1) A thin walled cylindrical vessel of wall thickness ‘t’ and diameter ‘d’ is filled with gas to a gauge pressure of ‘p’. The maximum shear stress on the vessel wall will then be**

a) pd/t

b) pd/2t

c) pd/4t

d) pd/8t

**2) A thin cylinder of unit length, thickness ‘t’ and radius ‘r’ is subjected to internal pressure ‘p’. What is the circumferential stress?**

a) pr/2Et

b) pr/2t

c) pr/t

d) 2pr/t

**3) The commonly used technique of strengthening thin pressure vessel is **

a) Wire winding

b) Shrink fitting

c) Autofrettage

d) Multi-layered construction

**4) Autofrettage is the method of**

a) joining thick cylinders

b) calculating stresses in thick cylinders

c) prestressing thick cylinders

d) increasing the life of thick cylinders

**5) For the same internal diameter, wall thickness, material and internal pressure, the ratio of maximum stress, induced in a thin cylindrical and in a thin spherical pressure vessel will be**

a) 2

b) ½

c) 4

d) ¼

**6) In a thick-cylinder pressurized from inside, the hoop stress is maximum at**

a) The center of the wall thickness

b) the outer radius

c) the inner radius

d) both the inner and the outer radii

**7) A thick cylinder is subjected to an internal pressure of 60 MPa. If the hoop stress on the outer surface is 150 MPa, then the hoop stress on the internal surface is**

a) 105 MPa

b) 180 MPa

c) 210 MPa

d) 135 MPa

**8) The ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to internal hydrostatic pressure is**

a) ½

b) 1

c) 2

d) 4

**9) Wahl’s factor takes into account**

a) Curvature of the helical wire

b) Direct shear stress

c) Both curvature and direct shear effect

d) Neither a nor b

**10) A spring of stiffness I KM/m is stretched initially by 100 mm from the under-formed position. The work required to stretch it by another 100 mm is**

a) 5Nm

b) 7 Nm

c) 10 Nm

d) 15 Nm