This set of Strength of Materials Multiple Choice Questions on “Combined Bending and Torsion”.
1. A solid shaft of circular in section is subjected to torque which produces maximum shear stress in a shaft. Calculate the diameter of the shaft.
a) (16T/πf)3/2
b) (16f/πT)1/2
c) (16f/π) 1/2
d) (πT/16f) 1/2
Answer: a
Clarification: From torsional equation
T/J = f/R
T = f.Z
T = f×π/16d3.
D= (16T/πf) 3/2.
2. When two dissimilar shafts are connected together, then the shaft is __________
a) Integrated shafts
b) Composite shafts
c) Differential shafts
d) Combined shafts
Answer: b
Clarification: When two dissimilar shafts are connected together to form one shaft then the shaft can be termed as composite shaft.
3. __________ torque occurs along with maximum shear stress due to combined bending and torsion.
a) Equipment
b) Coaxial
c) Biaxial
d) Lateral
Answer: a
Clarification: Equipment torque is the twisting moment which acts along producing maximum shear stress due to the combined bending as well as torsion.
4. When a shaft is subjected to pure twisting then the type of stress developed is ________
a) Bending
b) Axial
c) Shear
d) Normal
Answer: c
Clarification: Shear stress is produced when the shaft is subjected to pure twisting (torsion). The shear stress due to twisting moment is zero at the axis of the shaft.
5. The torque which produces unit twist per unit length is ________
a) Torsional rugosity
b) Torsional rigidity
c) Torsional viscosity
d) Torsional mean radius
Answer: a
Clarification: The product of shear modulus(C) and polar moment of inertia (J) is called torsional rigidity. Torsional rigidity produces a twist of 1 radian in a shaft of unit length.
6. The level of top of weir can be termed as __________
a) Talus
b) Curtain walls
c) Crest
d) Shutter
Answer: c
Clarification: The level of the top of weir is known as a crest. The shutters are provided on the crest and can be raised or laid flat during the time of floods.
7. ________ possesses less silting and scouring.
a) Weir
b) Barrage
c) Dams
d) Reservoir
Answer: b
Clarification: The barrage is a low obstructive barrier constructed across the river. There will be less silting and better control over the levels due to low set crest.
8. In __________ there will be no means for silt disposal.
a) Weir
b) Barrage
c) Reservoir
d) Dams
Answer: a
Clarification: The weir may be defined as a solid obstruction/wall built across the river to raise the water level. Raised crest causes silting at upstream and there is no means silt disposal.
9. _________ is a pure water pressure.
a) Uplift
b) Percolation
c) Scour
d) Flood bank
Answer: a
Clarification: Uplift occurs when pore water pressure under a structure or a low permeability confining layer becomes larger than the mean overburden pressure.
10. __________ causes of uplift of structure.
a) Percolation
b) Scour
c) Critical Velocity
d) Slope Failure
Answer: a
Clarification: The effect of percolation on an irrigation structure like a weir to cause uplift pressure on the structures and topple the structure at any moment.
11. ________ protects the weir from erosive forces during floods.
a) Talus
b) Curtain walls
c) Shutter
d) Upstream solid apron
Answer: d
Clarification: Upstream solid apron is a concrete bed which is provided on the upstream side of weir to protect the weir from erosive forces during floods. The length of apron depends upon maximum discharge of the river.
12. Gross storage – Dead storage is _______
a) Live storage
b) Virtual storage
c) Excessive storage
d) Free storage
Answer: a
Clarification: It is also called as available or effective storage. It is the difference between gross storage and dead storage. It is the amount of water available from FRL to the sill of the lowest sluice.
13. Which of the following is not sound proof?
a) G I sheets
b) A C sheets
c) PVC sheets
d) Fabric sheets
Answer: a
Clarification: Galvanised iron sheets are commonly used as a roofing material. These are very durable and fire proof. The main disadvantage is they are not sound proof.
14. Which of the following is not affected by temperature?
a) Fabric sheets
b) G I sheets
c) AC sheets
d) Flat roofs
Answer: c
Clarification: Asbestos cement sheets are cheaper in the initial cost. They are fire resisting. They are heavy in weight and they are not affected by temperature.
15. Which of the following possess good insulation properties?
a) Battened roofs
b) Wooden roofs
c) Jack arch roofs
d) Flat roofs
Answer: d
Clarification: Flat roofs are easier in construction and maintenance. A flat roof is more stable against high wards. It has a better architectural appearance and it has good insulation properties.