MCQ on Stresses & Strains in Thin Cylinder (SOM-CGPA)

Subject:- Strength of Material (SOM) 

Topic:- Thin Cylinder 

1. A cylinder is said to be thin if the ratio of its thickness and diameter, is less than

(a) 1/25

(b) 1/20

(c) 1/15

(d) 1/10

Answer: d

2. An open-ended cylinder of radius r and thickness t is subjected to internal pressure p. The Young's modulus for the material is E and Poisson's ratio is μ. The longitudinal strain is

(a) zero

(b) minimum

$\frac{pr}{\mathrm{/t}\mathrm{E<o:p></o:p><p></p>}}$

(c) maximum

$\frac{pr}{\mathrm{/2}t\mathrm{E<o:p></o:p><p></p>}}$

(d) none of these

 Answer: a

3. The stress in the wall of a cylinder in a direction normal to its longitudinal axis, due to a force acting along the circumference, is known as

(a) yield stress

(b) longitudinal stress

(c) hoop stress

(d) circumferential stress

 Answer: c

4. The ratio of the tensile stress developed in the wall of a boiler in the circumferential direction to the tensile stress in the axial direction, is

(a) 4

(b) 3

(c) 2

(d) 1

Answer: c

5. If p is the internal pressure in a thin cylinder of diameter d and thickness t, the developed hoop stress, is

(a) pd/2t

$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(b) pd/4t 

$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(c) pd/t 

$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(d) 2pd/t 

$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

 Answer: a

6. Pick up the correct statement from the following:

(a) Hoop strain of the walls of a cylinder due to liquid is pd/2tE(1-1/2m) 

(b) Longitudinal strain in the walls of a cylinder due to liquid is pd/2tE(1/2-1/m) h>

(c) Volumetric change in the cylinderdue to liquid is pd/2tE(5/2-2/m)

(d) All the above

 Answer: d

7. The ratio of circumferential stress to the longitudinal stress in the walls of a cylindrical shell, due to flowing liquid, is

(a) 1/2

(b) 1

(c) 3/2

(d) 2

 Answer: d

8. An isolated load W is acting at 'a' distance a from the left hand support, of a three hinged arch of span 2L and rise h hinged at the crown, the horizontal reaction at the support, is

(a) $\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(b) Wa/2h$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(c) $\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(d) 2h/Wa

$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

 Answer: b

9. The equation of a parabolic arch of span l and rise h, is given by

(a) y=hx/L²(L-x)

(b) y=2hx/L²(L-x)

(c) y=3hx/L²(L-x)

(d) y=4hx/L²(L-x)

 Answer: d

10. Volumetric strain of a sphere is

(a) Equal to diametric strain

(b) Twice the diametric strain

(c) Thrice the diametric strain

(d) One half of the diametric strain

 Answer: a

11. Shear strain is generally defined in terms of

(a) Deformation angle

(b) Increase in length

(c) Modulus of elasticity

(d) Shear modulus

 Answer: a

12. If a thin walled hollow spherical ball is placed in a pressure chamber, the stress in its wall will be

(a) Maximum along horizontal axis

(b) Uniform all over the shell

(c) Minimum along vertical axis

(d) Non uniform over the shell

 Answer: b

13. In a thin walled cylindrical pipe section having diameter 200mm and thickness 1mm, carries water at 5 N/mm2 pressure, hoop stress shall be

(a) 250 MPa

(b) 500 Mpa

(c) 125 MPa

(d) Zero

 Answer: d

14. In a thin walled cylindrical pipe section having radius 200mm and thickness 1mm, carries water at 5 N/mm2 pressure, longitudinal stress shall be

(a) 250 MPa

(b) 500 MPa

(c) 125 MPa

(d) Zero

 Answer: c

15. A long closed cylindrical pressure vessel is made by joining different cylindrical parts using lap joint all along the periphery. The rivets shall be under

(a) Bending shear

(b) Direct compression

(c) Direct shear

(d) Torsional shear

 Answer: c

16. A thin walled cylindrical pressure pipe is made by welding two semi circular parts along the length. Under working condition, the weld shall be under

(a) Direct shear

(b) Direct tension

(c) Direct compression

(d) Torsional shear

 Answer: a

17. In a thin walled closed cylindrical pressure vessel, bending moment will be

(a) Maximum near the end

(b) Maximum at the mid section

(c) Zero everywhere

(d) Uniform everywhere

 Answer: c

18. In all cylindrical pressure vessels, the ends are kept in form of hemisphere instead of circular plates. It is done to

(a) Avoid stress concentration

(b) Increase the capacity

(c) Reduce longitudinal stress

(d) Reduce hoop stress

 Answer: c

19. In a thin closed cylindrical pressure vessel, the ratio of hoop stress to longitudinal stress shall be

(a) 1

(b) 2

(c) 1/2

(d) 1/4

 Answer: b

20. In case of thin closed cylindrical pressure vessel, maximum shear stress shall be

(a) pd/2t$\frac{{\displaystyle \mathrm{<o:p></o:p><p></p>}}}{}$

(b) pd/4t$\frac{\mathrm{<o:p></o:p><p></p>}}{}$

(c) pd/6t$\frac{{\displaystyle \mathrm{<o:p></o:p><p></p>}}}{}$

(d) pd/8t$\frac{{\displaystyle \mathrm{<o:p></o:p><p></p>}}}{}$

 Answer: d

21. In a thin spherical shell, the ratio of radial to circumferential stress is

(a) 1/4

(b) 1/2

(c) 1

(d) 2

Answer: c