Engineering Questions with Answers - Multiple Choice Questions
Strength of Materials MCQs Kernel of a Section
The approximate percentage of steel taken for lintels in the absence of detailed design is _______
Explanation: RCC work maybe in foundations, columns, lintels, beams, floor& slabs the estimate is prepared in cubic metres. In absence of detailed design, the percentage of steel reinforcement is taken for lentils 0.7 to 1% and foundation raft footing it is 0.5 to 0.8%.
Mix proportion for M20 grade mix is _________
Explanation: Mix proportion for M20 grade mix is 1:1.5:3.
Grade of concrete Mix proportionate
The limit state corresponding to deflection, cracking and vibrations are _______
a) Limit state of collapse
b) Limit state of serviceability
c) Special limit state
d) Limit state of safety
Explanation: Limit state of serviceability refers to the ability of the structure at working loads it is the state of limit at which the structure undergoes heavy deflection which affects the finishes casting discomfort to the users.
In reinforcing of Steel bars, the end and side covers are taken as ____________ to ____________ mm.
a) 40 to 50mm
b) 30 to 45mm
c) 50 to 75mm
d) 35 to 50mm
Explanation: For reinforcement of Steel bars, the end and side covers are taken as 40 to 50 mm and the bottom and top covers 12 to 20 mm for slab and 25 to 50 mm for beams.
The field capacity of a soil depends upon _____________ factor.
a) Porosity of soil
b) Soil Tension
c) Saturation capacity
d) Initial regime
Explanation: The maximum amount of water content which can be held by soil particles against the force of gravity is called as field capacity. It is the upper limit of the capillary rise of water. It firmly depends on the porosity of soil.
According to Fannings formula the flood discharge in cumecs is given by Q = ______________
Explanation: The emperical formula for flood discharge given by various scientists is
i. Dicken’s – CA3/4
ii. Rvye’s – CA2/3
iii. Fannings – CA5/6.
The estimate of flood can be made by using ____________
a) Arithmetical increase method
b) Geometrical increase method
c) By unit hydrograph method
d) Comparison with graph method
Explanation: The estimation of a flood can be made by
i. Flood discharge formula
ii. By physical indication of past flood
iii. By unit hydrograph.
In simply supported slabs, alternate bars are curtailed at ________
a) 1/7 of span
b) 1/5 of span
c) 1/3 of span
d) 1/6 of span
Explanation: In simply supported beam at least 50% off bus shall extend into the support for a length of 1/3 of development length from the face of the support and the remaining alternate bars are curtailed at one sixth of span.
The length of the staircase between two consecutive landings is called _______
d) Effective width
Explanation: Stairs provide access for the various floors in a building. The stairs comprises series of steps with landings at appropriate intervals. The stretch between the two landings may be termed as a flight.
________ is used in the entrance of cinema theatres and shopping malls.
a) Open well stair case
b) Dog legged stair case
c) Geometrical stair case
d) Single flight stair case
Explanation: It is based on geometrical shape. The staircase is aesthetically superior compared to other types and generally used in the entrance of cinema theatres and shopping malls. This is mostly adopted in congested areas for good accessibility and proper ventilation.
In the design of lintel, determine the base angle of a triangle for poor masonry.
Explanation: It is assumed that the load of triangle portion of the masonry is considered to act on the lintel. The base angle of the triangle depends upon the quality of brick masonry used. It may be taken as 45°for good masonry and 60° for poor masonry.
Calculate the height of the equilateral triangle in the design of lintel, if the masonry used is poor graded. Take effective span as 1.29 m.
Explanation: Taking 60° [As masonry is of poor quality] Then height of equilateral triangle (h) = l × sin 60 °
= 1.29 × sin 60 °
For a simply supported beam, the basic l/d ratio should be ____________
Explanation: If the beam is being checked for deflection criteria, the basic values of l/d ratio of various beams should be
1. For Simply supported beam – 20
2. for cantilever beam – 7
3. for continuous beam – 26.
A beam of clear span 6 metres is supported on bearings of 150 mm if the effective depth of a beam is 400 mm. calculate the effective span.
Explanation: For calculation of effective span, the least of below values should be adopted:
1. Clear span + d = 6 + 0.4 = 6.4m
2. Clear span + bearings/2 + bearings/2 = 6+0.15/2+0.15/2 = 6.15m
The least of the above values is 6.15 metres. Hence effective span is 6.15 m.
The final deflection of horizontal members will be the level of casting should not exceed _____________
Explanation: The serviceability requirement for deflection should be such that final deflection of horizontal members below the level of casting should not exceed span / 250. This is the reason that the user can’t notice the deflection. The deflection taking place after construction of partitions should not exceed span / 350 or 20 mm whichever is less.
Strength of Materials MCQs Dams
The obstruction or a barrier built across the stream or river is called _____________
Explanation: A dam may be defined as an obstruction or a barrier built across the stream or river these are artificial storage works. It retains water to create an impounding reservoir.
FTL Stands for ________
a) Free tank level
b) Full tank level
c) Full top level
d) Fill toe level
Explanation: It is also called a full reservoir level (FRL). It is a level up to which the water stored obviously the crest of the spillway is fixed at this level.
_______ is openings extending from upstream to downstream of the dam.
a) Guide banks
b) Divide voids
Explanation: Sluices are openings or conduits extending from upstream face of the dam to downstream face of the dam. They are used to clean the silt from the reservoir. They also decrease the peak flood in the reservoir.
Water stored in dam is expressed in _______
a) Mega cumec metres
b) Million cubic metres
c) Metric cumec
d) Million cusec metres
Explanation: It is the total quantity of water stored up to FRL. It includes dead storage also. It is expressed generally in thousand hectare metre or million cubic metres (Mm3).
MDDL Stands for ________
a) Minimum draw down level
b) Maximum draw down level
c) Million drop down level
d) Mega drop down level
Explanation: It is the lowest level up to which the reservoir is depleted from the considerations of hydropower generation. So this level is known as minimum draw down level (MDDL).
_____ dam which resists are the external forces by virtue of its self weight.
a) Earthen dam
b) Storage dam
c) Detention dam
d) Gravity dam
Explanation: A gravity dam is that, which is stable against all the external forces achieved by the weight of the dam itself. This is the most permanent one and hence it is very commonly used. It may be constructed in all localities.
The factor of safety against overturning should not be less than ______
Explanation: In the dam section, the overturning takes place when a resultant force cuts the base of the dam downstream of the toe. The factor of safety against overturning is the ratio of the stabilizing moment to the overturning moments. The safety against overturning should not be less than 1.5.
In sliding failure, the co-efficient of friction varies from ________
a) 0.65 – 0.75
b) 0.8 – 0.9
c) 0.45 – 0.65
d) 0.85 – 1
Explanation: To avoid sliding, the factor of safety against the sliding should be greater than 1.
F.S = M(V-U) / €H > 1
Where M = Co-efficient of friction. It varies from 0.65 to 0.75
V = Total vertical force
U = Upward force.
Which of the following forces do not act on the dam?
a) Silt pressure
b) Wave pressure
c) Creep pressure
Explanation: Among the above forces, creep pressure does not act on the dam. Generally on gravity dam number of forces such as water pressure, wave pressure, wind pressure, ice pressure etc. will be acting in a horizontal direction. In the same way, uplift, self weight acts in vertical direction.
The elementary profile of a dam is generally a ________
a) Isosceles triangle
b) Right angled triangle
c) Scalene triangle
d) Equilateral triangle
Explanation: In the absence of any other forces, the forces due to water and self weight of the dam form an elementary profile which will be in triangular section having zero top width at water level, where the pressure is zero and maximum base width is at bottom where the maximum water pressure acts.
_____ acts as an inspection chamber in Dams.
c) Drainage gallery
Explanation: A drainage gallery is an opening in the body of a dam which runs longitudinally. It runs through the length of the dam. Generally, it is a rectangle shape with flat a semi-circular head usually 1.5 m wide and 2.5m height.
The minimum standard height for a construction joint is about ________
a) 1.2 m
b) 1.5 m
c) 2.1 m
d) 2.3 m
Explanation: The joints which facilitate construction of the dam to proceed in small lifts. These joints are also known as horizontal joints. A lift may be defined as the vertical distance between two consecutive construction joints. The height is about 1.5 m each.
Cracks developed in the body of dam section can be avoided by ________
a) Construction joints
b) Contraction joints
c) Transverse joints
d) Longitudinal joints
Explanation: Due to variation in temperature it causes contraction and expansion in masonry or concrete of the dam. It will develop fine cracks in the body of the dam. By providing contraction joints, these cracks can be avoided.
______ is the over flow section or portion of the dam.
Explanation: A spillway is the overflow section or portion of the dam over which surplus discharge flows from reservoir to downstream face. This structure is provided in the body of the dam or near the dam or on the periphery of the reservoir.
_______ is the common type of spillway used in gravity dams.
a) Ogee spillway
b) Trough spillway
c) Side channel spillway
d) Emergency spillway
Explanation: An ogee spillway is very common type of spillway used in gravity dams. It consists of two parts namely ¡)ogee crest and ¡¡) a bucket. In this spillway water spills and flows over and ogee crest in the form of a rolling sheet of water. Due to this, the development of negative pressures can be avoided.
Strength of Materials MCQs Rectangular Dam
Which of the following is not a failure of a rectangular dam?
b) Toe erosion
d) Foundation failure
Explanation: Among the above failures, the toe erosion is not related to rectangular dams. Toe erosion is caused due to in some cases the spillway is constructed very near to the dam section inside circumstances the discharge water may erode the dam.
Structural failures contribute about _______________ in the failure of dam.
Explanation: About 30% of failures are due to:
i. Foundation slide
ii. Upstream slope failure
iii. Downstream slope failure
iv. Failure due to flow slide.
The free board is provided in dams to avoid _______________
b) Foundation of upstream
c) Wave erosion
Explanation: By providing sufficient free board and by providing an adequate capacity of the spillway, failure due to overtopping of the damn can be avoided.
By providing ______________ gully formation can be avoided.
d) Free board
Explanation: By providing berms and turning on the downstream face of the dam, the failure due to the formation of the gullies can be avoided.
The maintenance of the reservoirs, above _____________ Ha comes under irrigation department.
Explanation: The maintenance of reservoirs is having commendable area below 40Ha comes under Panchayat Raj department and above 40 Ha come under irrigation department.
Which of the following process will you prefer to prevent the leakage of water in the dam foundation?
c) Gam mixing
Explanation: Grouting is a process in which a grout in liquid (8:1) slurry form, is injected into the soil under suitable pressures and applied through the pipes.
______ grouting increases the bearing capacity of soil.
d) Descending stage grouting
Explanation: According to functions served, the groutings can be classified into
i. Consolidated grouting
ii. Curtain grouting
iii. Area grouting
Consolidation grouting increases the bearing capacity of the soil and creates proper bonding between separated bodies.
According to IS, the specific gravity of a good building stone used in heavy dams should be ______
a) 2.2 – 2.4
b) 2.3 – 2.5
c) 2.4 – 2.8
d) 2.6 – 3
Explanation: The stones used for heavy irrigation works such as dams, bridges, check dams, weirs, docks should have specific gravity between 2.4 to 2.8. Stones used for the roof may have less specific gravity.
Hardness can be measured using _______
a) Mohr’s scale
b) Silica scale
c) Dalton’s scale
d) Abrasion factor
Explanation: The property to resist the abrasive forces cause due to wear & tear and friction is called hardness. It is determined by the Mohr’s scale of hardness in a laboratory. A hard stone will not show any scratches.
Granite has been widely used for dams construction because of _______
a) Crushing strength
Explanation: Granite stone is derived from igneous rocks. It is very hard, durable and strong. Its crushing strength is 100 to 140 N/mm^2. For this property, it is widely used in all important works.
The range of slenderness ratio in dams varies from ________
a) 13 – 15
b) 12 – 15
c) 15 – 18
d) 15 – 20
Explanation: In dams, the slenderness ratio can be calculated through
= Height of buttress / Thickness of buttress
• It varies from 12 to 15.
_______ is provided for installation of control equipment of valves in dams.
a) Vertical shafts
b) Hydraulic openings
c) Connecting passages
d) Isolated chambers
Explanation: Isolated chambers are provided for installation of control equipment of walls or pipeline or pumps. The function is to supply water to irrigation canals, fulfilling commitments and desilting the reservoir.
The ratio of the volume of voids to the volume of given soil mass is __________
b) Void ratio
c) Dry density
d) Specific gravity
Explanation: The porosity of a given soil sample is the ratio of the volume of voids to the value of given soil mass. It is denoted by “n”.
n = Vu / V.
Sand layer is an example of ______________
Explanation: An aquifer is a geologic formation (or) saturated bed which contains water and yields them significantly. Example: sand bed. They permit the appreciable quantity of water under ordinary field conditions.
________ keeps the phreatic line within the dam section.
a) Longitudinal filter
b) Cross filter
c) Rock toe
d) Toe drain
Explanation: Rock toe keeps the phreatic line within the damn section and also facilitates drainage. It is nothing but a downstream portion of a dam made of graded material. To achieve good results, the height of rock toe shall be kept 1/3 to 1/ 4 of dam height.