# Strength of Materials Questions and Answers – Thin Cylinder Under Strain

This set of Strength of Materials Multiple Choice Questions & Answers (MCQs) focuses on “Thin Cylinder Under Strain”.

1. Calculate the longitudinal strain, if internal pressure is 1.2 N/mm2 and 1 m in diameter along with 10 mm thickness. Take E = 2 × 105N/mm2and Poisson’s ratio as 0.3.
a) 0.00006
b) 0.0006
c) 0.006
d) 0.06

Explanation: Longitudinal strain = pd/2tE ×(1/2 – 1/m)
e = 1.2 ×1000 /2×10×2×105×(1/2 – 0.3)
e = 0.00006.

2. The radial stress in cylinder walls is negligible.
a) True
b) False

Explanation: The thickness of the plate is negligible compared to the diameter of shells in a shell is known as thin shell and in the thin shell, the radial stresses are negligible.

3. Distribution bars are also known as __________
a) Transverse bars
c) Flexural bars
d) Regant bars

Explanation: To resist the cracks due to variation of temperature and shrinkage stresses. The distribution bars are provided in addition to main bars along the shortest span. These bars are also known as transverse bars.

4. _______ is a saturated bed, which yields water.
a) Aquitard
b) Aquiclude
c) Aquifer
d) Aquifuge

Explanation: An aquifer is a saturated bed or geologic formation which yields water in significant quantities. The example for the aquifer is a sand bed.

5. _______ possesses free surface open to the atmosphere.
a) Aquitard
b) Aquifuge
c) Unconfined aquifer
d) Aquiclude

Explanation: An unconfined aquifer is one in which ground water process free open surface to the atmosphere. An aquifuge is an impervious formation that neither contains nor transmits water.

6. What is the porosity percentage in gravel?
a) 30 – 40 %
b) 50 – 60 %
c) 10 – 20 %
d) 1 – 10 %

Explanation: The porosity percentage in gravel is 30 – 40 %.

Materials Porosity
Clay 50 -60 %
Silt 40 – 50 %
Gravel 30 – 40 %

7. __________ is a measure of its water yielding capacity.
a) Specific capacity
b) Specific weight
c) Specific yield
d) Yield capacity

Explanation: The specific yield (Sy) of a material is a measure of its water yielding capacity and it is expressed quantitatively as a percentage of the total volume of material.

8. _______ is a measure of ease of flow of groundwater.
a) Permeability
b) Porosity
c) Voids ratio
d) Impermeability

Explanation: The permeability is a measure of ease of flow of groundwater through aquifers and aquitards and coefficient of permeability is the numbers of litres of water per day that will flow through a medium.

9. Piezometric surface is a ____________ surface.
a) Real
b) Imaginary
c) Stationary
d) Motive

Explanation: Piezometric surface is an imaginary surface to which water rises in wells tapping artesian aquifer.

10. _________ is a measure of the water retaining capacity of material (rock).
a) Specific capacity
b) Specific yield
c) Specific retention
d) Specific

Explanation: Specific retention is denoted by Sr (S suffix r). It is a measure of water retaining capacity.
Sr = Vr/V [Vr = Volume of water retained].

11. Draw down is also known as __________

Explanation: The difference in the level of the original water table and lowered water table due to pumping (or) drawing from a well is called draw down. It is also known as depression head.

12. The porosity range of sand stone be _________
a) 45 – 55 %
b) 20 – 25 %
c) 10 – 20 %
d) 1 – 10 %

Explanation: The porosity range of sand stone be 10 – 20 %.

Materials Porosity (%)
Gravel 30 – 40
Gravel and sand 20 – 25
Sand stone 10 – 20

13. Recuperation test is carried out to determine yield of well.
a) True
b) False

Explanation: Recuperation test K = 2.303 A/T log(H1/H2).
Q = KH
In this test, the water is first lower down to a safe level. The rise of water level and its corresponding time table is noted in a cross-sectional area of well different levels the yield of the well can be calculated.

14. Calculate thickness of metal, if the pressure inside the water main is 0.6 N/mm2. The diameter of water main is 600 mm. Take hoop stress = 25 N/mm2.
a) 7.20 mm
b) 9.45 mm
c) 10.58 mm
d) 12.24 mm

Explanation: Thickness of metal fc = pd/2t
t = pd / 2 fc ;
= 0.6 ×600 / 2 ×25
= 7.2 mm.

15. Ratio of lateral strain to linear strain is _________
a) Poisson’s ratio
b) Shear strength
c) Shear modulus
d) Bulk modulus

Explanation: The ratio of lateral strain to the corresponding longitudinal strain is called poisons ratio and it is denoted by 1 / m.
The value of poisons ratio for elastic materials is in the range of 0.25 to 0.33.

Sanfoundry Global Education & Learning Series – Strength of Materials.

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