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Past Questions — 2010
The diameter of bar of the column should not be less than
A)
12 mm
B)
10 mm
C)
8 mm
D)
6 mm
According to the Indian Standard code for reinforced concrete (IS 456:2000), specifically in the section regarding the design of columns, there are minimum requirements for the longitudinal reinforcement to ensure structural stability and prevent buckling. Clause 26.5.3.1 of IS 456:2000 explicitly states that the diameter of the longitudinal reinforcement bars in a column should not be less than 12 mm. This minimum diameter is specified to provide sufficient stiffness and to ensure that the bars can effectively resist the compressive loads and potential bending moments without excessive buckling. Options b (10 mm), c (8 mm), and d (6 mm) are below the minimum threshold required by the code for longitudinal column reinforcement.
Roller which consists of a steel cylindrical drum with steel projection extending in radial direction outward from the surface of the cylinder, is called
A)
smooth wheel roller
B)
sheep’s foot roller
C)
pneumatic type roller
D)
simple roller
A sheep's foot roller consists of a steel cylindrical drum with multiple steel projections (lugs or 'feet') extending radially outward from the surface. These projections penetrate the soil, providing compaction from the bottom up, which is particularly effective for cohesive soils like clay.
Comparison with other options:
- a. Smooth wheel roller: This has a smooth surface and is used for finishing or compacting granular soils.
- c. Pneumatic type roller: This uses rubber tires to provide a kneading action for compaction.
- d. Simple roller: This is a generic term and does not specifically describe the radial projection design characteristic of a sheep's foot roller.
The distance between the centres of adjacent rivets in the same row is called
A)
lap
B)
gauge
C)
staggered pitch
D)
pitch
In steel structure design and riveting, specific terminology is used to define the spacing of fasteners:
1. **Pitch (p):** This is defined as the distance between the centers of two adjacent rivets in the same row (parallel to the direction of the force). Therefore, option (d) is correct.
2. **Gauge (g):** This is the distance between the centers of adjacent rivets in two adjacent rows (perpendicular to the direction of the force).
3. **Staggered Pitch:** This refers to the distance between rivets in a zigzag pattern, specifically the longitudinal distance between rivets in adjacent rows.
4. **Lap:** This refers to the overlap of two plates being joined together, not the distance between rivets.
Since the question specifically asks for the distance between adjacent rivets in the same row, the correct technical term is 'pitch'.
p value of water to be used in concrete shall generally be
A)
not less than 5
B)
not less than 6
C)
not less than 7
D)
equal to 7
The pH value of water used for mixing and curing concrete is a critical factor in ensuring the durability and strength of the structure. According to standard engineering practices and specifications (such as IS 456 in India), the water used for concrete should be clean and free from harmful amounts of oils, acids, alkalis, salts, and organic materials. Specifically, the pH value of the water should not be less than 6.0. If the pH is too low (acidic), it can lead to the corrosion of the reinforcement steel and interfere with the hydration process of the cement, thereby reducing the overall strength and longevity of the concrete. Therefore, the requirement is that the pH value should be 'not less than 6'.
Geologically, marble is known as
A)
igneous rock
B)
metamorphic rock
C)
sedimentary rock
D)
stratified rock
Marble is a metamorphic rock that forms when limestone (a sedimentary rock) is subjected to the heat and pressure of metamorphism. This process causes the calcite in the limestone to recrystallize, resulting in a denser, coarser-grained rock.
Analysis of other options:
- a. Igneous rocks: These form from the cooling and solidification of magma or lava (e.g., granite, basalt). Marble does not form this way.
- c. Sedimentary rocks: These form from the accumulation of mineral or organic particles (e.g., limestone, sandstone). While marble originates from limestone, the process of metamorphism changes its classification.
- d. Stratified rocks: This is a general term for rocks that have distinct layers (strata), typical of sedimentary rocks. Marble, due to recrystallization, typically loses the original stratification of its parent limestone.
The stiffness factor for prismatic beam of length L and moment of inertia I, is
A)
2EI/L
B)
3EI/L
C)
4EI/L
D)
EI/L
In structural analysis, specifically within the Slope-Deflection Method, the stiffness of a member is defined as the force or moment required to produce a unit displacement or rotation. For a prismatic beam (a beam with a constant cross-section and moment of inertia I) of length L, the rotational stiffness depends on the boundary conditions of the far end:
1. If the far end is FIXED, the stiffness is k = 4EI/L. This is the standard 'stiffness factor' used in the general slope-deflection equations for a member where the far end is restrained against rotation.
2. If the far end is HINGED (pinned), the stiffness is k = 3EI/L.
In the context of general structural analysis textbooks and competitive exams, when the 'stiffness factor' of a prismatic beam is asked without specifying the far-end condition, it refers to the standard stiffness used in the slope-deflection equation for a member fixed at both ends, which is 4EI/L.
- Option (a) 2EI/L is not a standard stiffness factor for a single beam member.
- Option (b) 3EI/L is the stiffness for a beam with a pinned far end.
- Option (d) EI/L is related to the flexural rigidity but not the rotational stiffness factor.
Seasoning of timber is necessary to
A)
increase the fire resistance
B)
increase the vermin resistance
C)
reduce the microbial substances
D)
expel the moisture in the timber
Seasoning of timber is the process of reducing the moisture content (sap) of the wood to a level that is in equilibrium with the environment in which the timber will be used. Freshly felled timber contains a high percentage of water (sap), which can lead to warping, shrinking, cracking, and decay if not removed. By expelling this moisture—either through natural air drying or artificial methods like kiln drying—the timber becomes more dimensionally stable, stronger, and more durable.
Analysis of other options:
- Option (a): Seasoning does not inherently increase fire resistance; fire resistance is typically improved through chemical treatments or charring.
- Option (b): While seasoned timber is less prone to certain pests than wet timber, the primary purpose of seasoning is not vermin resistance; that is the goal of 'preservation' (e.g., using creosote).
- Option (c): Reducing microbial substances is a byproduct of removing moisture (as fungi need moisture to grow), but the fundamental definition and primary objective of seasoning is the removal of moisture.
Black marble is generally found in the district of
A)
Jodhpur
B)
Jabalpur
C)
Jaipur
D)
Jaisalmer
Black marble is a distinctive geological resource found in the Jaisalmer district of Rajasthan, India. Jaisalmer is world-renowned for its high-quality yellow sandstone and specific varieties of black and golden marble.
Analysis of options:
- Jodhpur: Primarily known for Jodhpur sandstone (red/pinkish).
- Jabalpur: Known for marble (specifically the Bhedaghat white marble), but not the primary source of black marble.
- Jaipur: Known for various colored marbles and gemstones, but not the primary source of the specific 'black marble' associated with the western desert region.
- Jaisalmer: The geological formations in this region provide the specific mineral composition required for the production of black marble.
A beam is defined as a structural member subjected to
A)
axial loading
B)
transverse loading
C)
axial and transverse loading
D)
none of the above
In structural mechanics, a beam is specifically defined as a structural member designed to support loads applied perpendicular to its longitudinal axis. These loads are known as transverse loads. When a beam is subjected to transverse loading, it primarily undergoes bending (flexure) and shear stress.
Comparing the options:
- Option (a) 'axial loading' describes a member like a column or a tie/strut, where the force acts along the longitudinal axis, causing tension or compression.
- Option (b) 'transverse loading' is the defining characteristic of a beam, as it induces the bending moment that beams are designed to resist.
- Option (c) 'axial and transverse loading' describes a 'beam-column'. While a beam can technically experience both, the fundamental definition of a beam focuses on its capacity to carry transverse loads.
- Option (d) is incorrect because option (b) is the standard engineering definition.
According to Rankine’s formula of earth pressure on a retaining wall of h and with other usual notations, is
A)
wh2 / 2 * (1 - sin phi)
B)
wh2 / 2 * (1 + sin phi)
C)
wh2 / 4 * (1 + sin phi)
D)
wh2 / 2 * (1 - sin phi)
According to Rankine's theory of earth pressure, the active earth pressure coefficient (Ka) for a cohesionless soil with an angle of internal friction (phi) is given by: Ka = (1 - sin phi) / (1 + sin phi). The active earth pressure at a depth 'h' is p = Ka * w * h, where 'w' is the unit weight of the soil. The total active thrust (Pa) acting on the wall is the integral of the pressure over the height, which results in the area of the pressure triangle: Pa = 1/2 * Ka * w * h^2. Substituting Ka = (1 - sin phi) / (1 + sin phi), the formula becomes Pa = (w * h^2 / 2) * [(1 - sin phi) / (1 + sin phi)]. Looking at the provided options, option (a) represents the numerator part of the coefficient (1 - sin phi) multiplied by the pressure triangle area (wh^2/2). While the full Rankine formula typically includes the (1 + sin phi) in the denominator, in the context of these specific multiple-choice options, option (a) is the intended answer as it correctly identifies the 'active' pressure relationship (1 - sin phi). Option (b) would relate to passive pressure (1 + sin phi). Note: There is a typo in the options provided in the source exam where (a) and (d) are identical, but (a) is the standard selection for active pressure components.
The maximum bending moment due to moving load on a simply supported beam occurs
A)
at the mid span
B)
at supports
C)
anywhere in the beam
D)
under the load
For a simply supported beam of length L, the bending moment at any section x from the left support due to a single concentrated moving load P is given by the formula M = (P * a * b) / L, where 'a' is the distance of the load from the left support and 'b' is the distance from the right support. To find the absolute maximum bending moment as the load moves across the beam, we analyze the moment at the center (x = L/2). When the load P is positioned exactly at the mid-span (x = L/2), the bending moment is M_max = (P * (L/2) * (L/2)) / L = PL/4. This is the highest possible bending moment that can occur at any point in the beam for a single moving point load. While the maximum moment 'under the load' varies as the load moves, the absolute maximum value across the entire beam's length and the load's travel path occurs specifically when the load is at the mid-span.
In plastic analysis, the shape factor for rectangular section is
A)
1.7
B)
1.6
C)
1.5
D)
1.4
In plastic analysis of steel structures, the Shape Factor (S) is defined as the ratio of the Plastic Moment (Mp) to the Yield Moment (My).
1. **Yield Moment (My):** This is the moment at which the outermost fiber of the section first reaches the yield stress (fy). For a rectangular section of width 'b' and depth 'd', the section modulus (Z) is (b * d^2) / 6. Therefore, My = fy * Z = fy * (b * d^2) / 6.
2. **Plastic Moment (Mp):** This is the moment when the entire cross-section has reached the yield stress, forming a plastic hinge. The plastic section modulus (Zp) for a rectangle is the sum of the first moments of area above and below the plastic neutral axis. Zp = (b * d^2) / 4. Therefore, Mp = fy * Zp = fy * (b * d^2) / 4.
3. **Calculation of Shape Factor (S):**
S = Mp / My
S = [fy * (b * d^2) / 4] / [fy * (b * d^2) / 6]
S = (1/4) / (1/6) = 6 / 4 = 1.5.
Thus, the shape factor for a rectangular section is 1.5. Options a, b, and d are incorrect as they do not match the derived geometric ratio for a rectangle.
If T and R are respectively tread and rise of a stair, then
A)
2R+T=60
B)
R+2T=60
C)
2R+T=30
D)
R+2T=30
In building construction and architectural design, the dimensions of a stair (the rise 'R' and the tread 'T') are governed by ergonomic principles to ensure a comfortable and safe gait for the user. The most widely accepted empirical formula for the design of residential and public stairs is the 'Blondel's Rule' or the 'Rule of Thumb' for stair proportions. The standard formula is: 2R + T = 600 mm (or 630 mm depending on the specific code, but 60 cm is the classic standard). Converting 600 mm to centimeters gives 60 cm. Therefore, the relationship is 2R + T = 60.
- Option (a) 2R + T = 60 is the correct standard formula.
- Option (b) R + 2T = 60 is incorrect as it would result in an unnaturally deep tread and a very low rise.
- Options (c) and (d) are incorrect because a value of 30 cm is far too small for the combined sum of two rises and one tread, which would result in a stair that is impossible for a human to climb.
The maximum range of the chemicals in cement is
A)
silica (SiO2)
B)
Alumina (Al2O3)
C)
magnesia (MgO)
D)
Lime (CaO)
Portland cement is composed of several chemical compounds. The 'maximum range' refers to the chemical constituent present in the highest percentage by weight. The typical chemical composition of Ordinary Portland Cement (OPC) is as follows:
1. Lime (CaO): 60% to 67% (The primary ingredient)
2. Silica (SiO2): 17% to 25%
3. Alumina (Al2O3): 3% to 8%
4. Iron Oxide (Fe2O3): 0.5% to 6%
5. Magnesia (MgO): 3.5% to 4%
6. Sulfur Trioxide (SO3): 1% to 3%
Since Lime (CaO) constitutes the largest portion of the cement mixture, it has the maximum range among the given options. Lime is responsible for the strength and soundness of the cement, although an excess can cause unsoundness (expansion).
Common pumps used in building, building constructions are
A)
centrifugal
B)
Submersible
C)
air jet
D)
all the above
In building and building construction, different types of pumps are required depending on the specific application (dewatering, water supply, or specialized lifting).
1. Centrifugal Pumps: These are the most common pumps used for general water transfer and supply systems in buildings due to their simplicity and efficiency in moving large volumes of water.
2. Submersible Pumps: These are essential in construction for 'dewatering' (removing water from excavations, basements, or trenches) and are also used in deep-well water supply systems where the pump must be submerged in the fluid.
3. Air Jet Pumps: These are used in specific construction scenarios, such as lifting water from deep wells or removing water from areas where electrical pumps might be hazardous or impractical, using compressed air to create a vacuum.
Since all three types of pumps are utilized across various stages and requirements of building construction, the correct option is 'all the above'.
The allowable stress in axial tension is generally kept less if thickness of the member is more than
A)
10 mm
B)
12 mm
C)
15 mm
D)
20 mm
In structural steel design, the allowable stress for members in tension is influenced by the thickness of the material. For thinner sections, the material is more homogeneous. However, as the thickness of the steel member increases, the risk of internal flaws, impurities, and non-uniformity in the rolling process increases. Specifically, in many standard design codes (such as older versions of IS codes or general structural engineering practice), when the thickness of a tension member exceeds 20 mm, the allowable tensile stress is reduced to provide a higher factor of safety against these potential internal defects and to account for the reduced ductility in the core of thicker sections. Therefore, the allowable stress is generally kept lower if the thickness exceeds 20 mm.
If a shaft is simultaneously subjected to a torque T and bending moment M, the ratio of maximum bending stress is
A)
M/T
B)
2M/T
C)
T/M
D)
2T/M
To find the ratio of maximum bending stress to maximum shear stress for a solid circular shaft, we use the standard formulas for stress:
1. **Maximum Bending Stress (σb):** For a shaft of diameter 'd', the bending stress is given by:
σb = (32M) / (πd³)
2. **Maximum Shear Stress (τ):** For a shaft of diameter 'd', the torsional shear stress is given by:
τ = (16T) / (πd³)
3. **Calculating the Ratio:**
Ratio = σb / τ
Ratio = [(32M) / (πd³)] / [(16T) / (πd³)]
Ratio = (32M) / (16T)
Ratio = 2M / T
Therefore, the ratio of the maximum bending stress to the maximum shear stress is 2M/T. Note: The question phrasing 'ratio of maximum bending stress' is slightly elliptical and implies the ratio of bending stress to shear stress, which is the standard engineering comparison for shafts under combined loading.
As per ISI, rolled steel beam section are classified into
A)
two series
B)
three series
C)
four series
D)
five series
According to the Indian Standard (IS) specifications for rolled steel sections (specifically IS 808), rolled steel beam sections (I-beams) are classified into three distinct series based on their depth-to-flange width ratios and weight per unit length. These are: 1. Light series (Lightweight sections), 2. Medium series (Standard sections), and 3. Heavy series (Heavy-duty sections). These series allow engineers to select a beam that optimizes the strength-to-weight ratio based on the specific loading conditions of the structural member. Options a, c, and d are incorrect as they do not align with the standard classification system used in the ISI rolled steel tables.
According to I S : 456 speculations, the safe diagonal tensile stress for M 150 grade concrete, is
A)
50 N/cm2
B)
100 N/cm2
C)
150 N/cm2
D)
200 N/cm2
According to IS 456 (the Indian Standard code for Plain and Reinforced Concrete), the permissible diagonal tensile stress (also known as the principal tensile stress) for concrete is specified based on the grade of concrete. For M 150 grade concrete (which corresponds to a characteristic compressive strength of 150 kg/cm² or approximately 15 MPa), the safe diagonal tensile stress is specified as 100 N/cm².
Calculation/Reference:
1. M 150 grade concrete refers to a concrete with a characteristic strength of 150 kg/cm².
2. In the context of working stress design (which was prevalent in older versions of the code and often tested in these specific exam formats), the permissible principal tensile stress for M 150 is 100 N/cm².
3. Converting units: 100 N/cm² is equivalent to 1.0 MPa.
Comparing with options:
- Option (a) 50 N/cm² is too low for M 150.
- Option (b) 100 N/cm² matches the IS 456 specification for M 150.
- Option (c) 150 N/cm² and (d) 200 N/cm² exceed the safe limits for this grade of concrete.
In rolled steel beams, shear force is mostly resisted by
A)
web only
B)
flange only
C)
web and flange together
D)
none of the above
In a rolled steel beam (such as an I-beam or H-beam), the cross-section consists of two flanges and a connecting web. The distribution of internal forces is as follows: 1. Bending Moment: The flanges are located furthest from the neutral axis, meaning they have the highest moment of inertia and are primarily responsible for resisting the bending moment (compression and tension). 2. Shear Force: The shear stress distribution in an I-section is parabolic, but the vast majority of the shear area is concentrated in the vertical web. Mathematically, the shear stress (τ) is given by τ = VQ/Ib. Since the web has a much smaller width (b) compared to the flanges and carries the bulk of the first moment of area (Q) for the majority of the section's height, the web resists nearly all (typically over 90-95%) of the vertical shear force. Therefore, for practical engineering purposes, it is considered that the web resists the shear force while the flanges resist the bending moment.
The rocks which were formed by gradual deposition are called
A)
sedimentary rocks
B)
metamorphic rocks
C)
igneous rocks
D)
none of the above
The classification of rocks is based on their mode of formation.
1. **Sedimentary Rocks (Option a):** These rocks are formed through the process of lithification, where sediments (small particles of rocks, minerals, or organic matter) are transported by wind, water, or ice and deposited in layers over time. This 'gradual deposition' and subsequent compaction and cementation is the defining characteristic of sedimentary rocks (e.g., sandstone, limestone, shale).
2. **Metamorphic Rocks (Option b):** These are formed when existing rocks (igneous, sedimentary, or other metamorphic rocks) are subjected to intense heat and pressure, causing a physical or chemical change in the rock's structure without melting it.
3. **Igneous Rocks (Option c):** These are formed from the cooling and solidification of molten rock (magma or lava), not by deposition.
Therefore, rocks formed by gradual deposition are exclusively sedimentary rocks.
Design of two-way slab simply supported on edges and having no provision to prevent the corners from lifting, is made by
A)
Marcus formula
B)
Rankine formula
C)
Grashoff formula
D)
Rankine Grashoff formula
In the design of two-way slabs, the distribution of loads between the two orthogonal directions depends on the boundary conditions (support conditions). When a two-way slab is simply supported on all four edges and there is no provision to prevent the corners from lifting (i.e., the corners are free to lift), the load distribution is calculated using the Rankine-Grashoff theory. This theory assumes that the slab behaves as two independent sets of beams acting in perpendicular directions. The load shared by each direction is inversely proportional to the stiffness of the slab in that direction. Specifically, the formula relates the load distribution to the ratio of the spans (Lx and Ly).
- Marcus formula is typically associated with the design of slabs with specific boundary constraints or different structural elements.
- Rankine and Grashoff individually contributed to the theory of load distribution in plates, but the combined 'Rankine-Grashoff' method is the standard classical approach for simply supported two-way slabs without corner restraints.
Tractor that moves on endless chain is called
A)
pneumatic type tractor
B)
track type tractor
C)
wheel type tractor
D)
none of the above
In construction equipment, tractors are categorized based on their propulsion system.
1. **Track Type Tractor (Crawler Tractor):** These machines move on continuous, endless chains (tracks) made of steel or rubber. The tracks distribute the weight of the machine over a larger area, reducing ground pressure and providing superior traction and stability on soft, muddy, or uneven terrain. This matches the description 'moves on endless chain'.
2. **Wheel Type Tractor:** These use rubber tires (pneumatic tires) and are designed for higher speeds and mobility on hard surfaces, but they have higher ground pressure and less traction in soft soil compared to track types.
3. **Pneumatic Type Tractor:** This is essentially a subset of wheel-type tractors that specifically use air-filled (pneumatic) tires.
Therefore, the specific term for a tractor moving on an endless chain is a track type tractor.
Time of completion of project in bar charts is shown by
A)
vertical lines
B)
horizontal lines
C)
crosses
D)
none of the above
In project management, a Bar Chart (also known as a Gantt Chart) is a tool used to represent the project schedule. In this chart, the vertical axis (Y-axis) typically lists the activities or tasks, while the horizontal axis (X-axis) represents the time scale (days, weeks, or months). Each activity is represented by a horizontal bar; the length of this bar indicates the duration of the activity, and its position along the horizontal time axis shows the start and finish times. Therefore, the time of completion and the duration of the project are depicted by horizontal lines (bars). Vertical lines are typically used as grid lines to mark specific dates or milestones, but the actual representation of the project's time progress and completion for each task is shown by the horizontal bars.
Most commonly used solvent in oil paints is
A)
spirit
B)
petroleum
C)
turpentine
D)
coal tar
Oil paints consist of a pigment suspended in a drying oil (typically linseed oil). Because oil paints are hydrophobic (do not mix with water), a non-polar organic solvent is required to thin the paint and clean the brushes. Turpentine, a fluid obtained by the distillation of resin from live trees (mainly pines), is the most traditional and commonly used solvent for oil-based paints. It effectively dissolves the oil medium and evaporates at a rate suitable for the painting process.
Analysis of other options:
- Spirit (e.g., Mineral Spirits or Methylated Spirits): While mineral spirits are used as a modern alternative to turpentine, 'spirit' is a broad term. Turpentine is the classic and most specific answer for traditional oil paints.
- Petroleum: While some solvents are petroleum-derived, raw petroleum is not used as a paint solvent due to its impurities and consistency.
- Coal tar: This is a thick, viscous byproduct of coal carbonization used in road surfacing and roofing, not as a solvent for paints.