Engineering Questions with Answers - Multiple Choice Questions

# Strength of Materials (MCQs) focuses on “Strain”

1 - Question

The moment of inertia of a plane area with respect to an axis ____________ to the plane is called a polar moment of inertia.
a) Parallel
b) Perpendicular
c) Equal
d) Opposite
Explanation: The moment of inertia of a plane area with respect to an axis perpendicular to the plane of the figure is called a polar moment of inertia with respect to a point, where the axis intersects a plane.

2 - Question

What are the units of Polar modulus?
a) mm3
b) mm2
c) mm
d) mm4
Explanation: The ratio of polar moment of inertia (J) to the radius of section(R) is known as polar modulus or torsional section modulus. Its units are mm3.

3 - Question

What is the polar modulus for solid shaft?
a) π/16 D2
b) π/12 D3
c) π/ 16 D3
d) π/16 D
Explanation: For solid shaft Z = J/R = π/32 × D4/ D/2. Z = π/16 D3.

4 - Question

Calculate the polar moment of inertia for a solid circular shaft of 30 mm diameter.
a) 76m4
b) 79.5m4
c) 81m4
d) 84m4
Explanation: Diameter of the shaft = 30 mm Polar moment of inertia = J = π/32 × (30)4 mm4 J = 79.52 m4.

5 - Question

A hollow shaft outside diameter 120 mm and thickness 20 mm. Find polar moment of inertia.
a) 16.36 × 106 mm4
b) 18.45 × 106 mm4
c) 21.3 × 106 mm4
d) 22.5 × 106 mm4
Explanation: For hollow circular shaft, outside diameter = 120 mm; d = 120-2×20 = 80 mm the polar moment of inertia = π/32 × (1204– 804). J = 16.36 × 106 mm4.

6 - Question

Determine the maximum flood discharge from a catchment area of 40.25 km2 and it is situated in the Western Ghats.
a) 350 cumecs
b) 375 cumecs
c) 400 cumecs
d) 425 cumecs
Explanation: Since the catchment area is situated in the Western Ghats, the formula best suited is Dicken’s formula and the coefficient of Dicken’s may be taken as 25. Q = CA3/4 Q = 25×(40.25)3/4 Q = 400 cumecs.

7 - Question

Which of the following is known as “under sluices”?
a) Scouring Sluices
b) Divide wall
Explanation: The openings provided in a body wall of the weir almost at the bed level of the river are known as scouring sluices. These are also known as under sluices.

8 - Question

_______ provides straight approach to the scouring sluices.
b) Silt Excluder
c) Divide wall
d) Guide banks
Explanation: A divide wall is a long solid wall constructed perpendicular to the axis of weir. It provides a straight approach to the scouring sluices. By preventing the formation of cross currents, it protects the body wall of weir.

9 - Question

__________ is provided for the easy movement of fish from upstream to downstream.
b) Silt excluder
c) Marginal bunds
d) Marginal embankments
Explanation: A passage provided just by the side of a divide wall for the movement of fish from upstream to downstream or vice versa is known as a fish ladder.

10 - Question

__________ is used as measuring device.
b) Divide wall
c) Cross regulator
d) Scouring sluices
Explanation: A structure constructed at the head of the canal to regulate the supply of water into the canal is called “Head Regulator”. The functions: i. It is used as a measuring device. ii. It controls the entry of silt into the canal.

11 - Question

__________ is provided to prevent the river from outflanking the work.
a) Guide banks
b) Marginal bunds
c) Silt excluder
d) Divide wall
Explanation: Guide banks are provided on either side of the diversion head works in alluvial soils for a smooth non -tortuous approach to the diversion head works and prevent the river from outflanking the work.

12 - Question

____________ are provided to protect the land and property with is likely to be submerged.
a) Weir
b) Divide wall
c) Marginal bunds
Explanation: Marginal Bunds or marginal embankments are provided on either bank of the river upstream side of diversion head works in alluvial soils in order to protect the land and property which is likely to be submerged during ponding of water during floods.

13 - Question

_________ is provided to reduce the kinetic energy of falling water in weir.
a) Body wall
b) Curtain walls
c) Downstream apron
d) Shutter
Explanation: The downstream apron is a concrete bed which is provided on the downstream side of a weir in order to reduce the kinetic energy of falling water. It should have sufficient thickness to resist uplift pressure.

14 - Question

Curtain walls are provided to increase ________
a) Creep depth
b) Creep area
c) Creep length
d) Creep volume
Explanation: Curtain walls are provided under the upstream and downstream apron at the ends. We are provided to increase the length of creep and thereby to reduce exit gradient.

15 - Question

Which of the following are also known as upstream and downstream piles?
a) Talus on upstream and downstream
b) Curtain walls on upstream and downstream
c) Solid apron on upstream and downstream
d) Shutters on crest of weir
Explanation: Curtain walls are provided especially under the upstream and downstream aprons at the respective ends. They are also called as upstream and downstream piles. The length of the curtain wall depends on the nature of subsoil.

16 - Question

A circular shaft of diameter 30 mm is tested under torsion the gauge length of test specimen is 300 mm. A torque of 2kNm produces an angle twist of 1°. Calculate CJ.
a) 0.432 × 106 N/mm2
b) 0.324 × 106 N/mm2
c) 0.46 × 106 N/mm2
d) 0.532 × 106 N/mm2
Explanation: Angle of twist = 1° = π/180 radians. Polar moment of inertia = π/32 × 304mm4. To find CJ: T/J =C× twist angle C = Tl/J×twist angle = 2×106 ×300 / π/32 × 304mm4× π/180. C = 0.4323 × 106 N/mm2.

17 - Question

__________ has perfect control on river flow.
a) Barrage
b) Weir
c) Marginal bunds
d) Guide banks
Explanation: Barrages are much more costly than weirs. Gates are raised off the high flood to pass floods. They have perfect control of the river flow.

18 - Question

When the gross length is more than 6 metres between the face of abutment it is called as ________
a) Cause way
b) Bridge
c) Culvert
d) Cassion
Explanation: When the gross length is more than 6 m between the faces of abutment measured at right angles is called a bridge. If a bridge supports a road way over a railway then it is called Road over a bridge.

19 - Question

The minimum straight approach provided on either side of bridge is ___________
a) 12 m
b) 15 m
c) 20 m
d) 22 m
Explanation: The bridge site should be far away from the confluence of tributaries as far as possible the straight approaches are to be provided on either side of the bridge for at least 15m.

20 - Question

________ should be taken below the deepest scour level.
a) Foundation
b) Sub structure
c) Structure
d) Parapet
Explanation: Foundations to be provided for approaches abutments, piers etc., by considering the water in the river, sub soil conditions etc., a foundation should be taken below the deepest scour level.

21 - Question

___________ formula is used for calculating the depth of the foundation.
a) Gordon’s
b) Rankine’s
c) WH Smith’s
d) Falcon
Explanation: Rankine’s formula is used for calculating the depth of the foundation. h=P/w × (1-sin/1+sin). Minimum depth is restricted to 90 cms.

22 - Question

_______ foundation is used when the depth of water is more.
a) Pile
b) Caisson
c) Raft
Explanation: The caisson foundation is used when the depth of water is more. The spread Foundation is used when good hard soil is available at shallow depth.

23 - Question

_____________ foundation is used when bed soil is soft.
a) Raft
b) Pile
d) Well
Explanation: Pile foundation is adopted when the bed soil is soft and hard soil is available at great depth and also the well foundation is adopted when river bed having sand and good soil is available at a reasonable depth.

24 - Question

The intermediate support of a bridge superstructure is called as ___________
a) Abutment
b) Pier
c) Wing wall
d) Approach
Explanation: The intermediate support of bridge superstructure for a multi span bridge is called pier. Functions: i. To divide the total length of bridge into suitable spans. ii. To distribute the load from the superstructure of the bridge.

25 - Question

___________ piers are adopted for well foundations.
a) Masonry
b) RCC
c) Dumb bell
d) Pile bent
Explanation: Dumb-bell piers are light in weight as compared to solid piers. These piers are suitable when well foundations are adopted. It consists of two columns connected by web for the full height.

26 - Question

_______ piers are used, when the height of pier is large as in case of viaducts, fly overs.
a) Column Bent
b) Pile bent
c) Trestle bent
d) Abutment pier
Explanation: It consists of vertical, horizontal and diagonal members. Trestle bents may be of steel or concrete. These piers are suitable when the height of pier is large as in case of viaducts.

27 - Question

The projection of the piers on the upstream side is known as ________
a) Cut waters
b) Ease waters
c) Sharp waters
d) Para waters
Explanation: The projection of the piers on the upstream side is known as cut waters. The cut waters are provided for easy passage of water. The shape may be triangular, semi-circular & parabolic etc.

28 - Question

The end support of a bridge is __________
a) Pier
b) Abutment
c) Wing wall
d) Approach
Explanation: The end support of a bridge superstructure is known as an abutment. The functions of abutment are i. To retain the earth filling of approaches ii. To finish up the bridge with necessary approaches.

29 - Question

The projection of the pier on the downstream side is known as ________
a) Ease water
b) Cut water
c) Bridge pier
d) Dumb pier
Explanation: The projection of the pier on the downstream side is known as “ease waters”. They prevent the formation of eddies and their scouring effect.

30 - Question

____________ piers are suitable when foundations are of steel cylinder caisson type.
a) Masonry
b) Trestle bent
c) Cylindrical
d) Pile
Explanation: Cylindrical piers are made of mild steel filled with concrete and connected by horizontal and diagonal steel bearings. These are suitable when foundations of Steel cylinder caisson type.

31 - Question

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
Explanation: From torsional equation T/J = f/R T = f.Z T = f×π/16d3. D= (16T/πf) 3/2.

32 - Question

When two dissimilar shafts are connected together, then the shaft is __________
a) Integrated shafts
b) Composite shafts
c) Differential shafts
d) Combined shafts
Explanation: When two dissimilar shafts are connected together to form one shaft then the shaft can be termed as composite shaft.

33 - Question

__________ torque occurs along with maximum shear stress due to combined bending and torsion.
a) Equipment
b) Coaxial
c) Biaxial
d) Lateral
Explanation: Equipment torque is the twisting moment which acts along producing maximum shear stress due to the combined bending as well as torsion.

34 - Question

When a shaft is subjected to pure twisting then the type of stress developed is ________
a) Bending
b) Axial
c) Shear
d) Normal
Explanation: 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.

35 - Question

The torque which produces unit twist per unit length is ________
a) Torsional rugosity
b) Torsional rigidity
c) Torsional viscosity
Explanation: 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.

36 - Question

The level of top of weir can be termed as __________
a) Talus
b) Curtain walls
c) Crest
d) Shutter
Explanation: 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.

37 - Question

________ possesses less silting and scouring.
a) Weir
b) Barrage
c) Dams
d) Reservoir
Explanation: 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.

38 - Question

In __________ there will be no means for silt disposal.
a) Weir
b) Barrage
c) Reservoir
d) Dams
Explanation: 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.

39 - Question

_________ is a pure water pressure.
a) Uplift
b) Percolation
c) Scour
d) Flood bank
Explanation: Uplift occurs when pore water pressure under a structure or a low permeability confining layer becomes larger than the mean overburden pressure.

40 - Question

__________ causes of uplift of structure.
a) Percolation
b) Scour
c) Critical Velocity
d) Slope Failure
Explanation: 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.

41 - Question

________ protects the weir from erosive forces during floods.
a) Talus
b) Curtain walls
c) Shutter
d) Upstream solid apron
Explanation: 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.

42 - Question

Gross storage – Dead storage is _______
a) Live storage
b) Virtual storage
c) Excessive storage
d) Free storage
Explanation: 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.

43 - Question

Which of the following is not sound proof?
a) G I sheets
b) A C sheets
c) PVC sheets
d) Fabric sheets
Explanation: 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.

44 - Question

Which of the following is not affected by temperature?
a) Fabric sheets
b) G I sheets
c) AC sheets
d) Flat roofs
Explanation: 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.

45 - Question

Which of the following possess good insulation properties?
a) Battened roofs
b) Wooden roofs
c) Jack arch roofs
d) Flat roofs