Question: What is the reaction at support B, if support B of fixed beam AB sinks by an amount δ?
Answer: 12EIδ/L3.
As the support B sinks by δ, anticlockwise moment of 6EI δ/L2 is induced at point A and B. Taking sum of moment at A equal to zero we get vertical reaction at B as 12EL δ/L3
Question: What is modulus of rupture?
Answer: The ultimate strength in flexure or in torsion is knows as modulus of rupture.
Question: What is the minimum reinforcement in case of Fe415 steel in slab?
Answer:
- 0.12% of gross area with Fe415
- 0.15% of gross area with Fe250.
Question: For a beam of with b and depth D subjected to torsional moment Tu and shear force VU, what is the equivalent shear force ?
Answer: Ve= VU + 1.6 Tu/b
Equivalent nominal shear stress = Ve/bd
Question: What is coefficient of compression(CC) for undisturbed soil sample?
Answer:
- Cc= 0.009(wL-10%) , for undisturbed soil sample or field consideration
- Cc= 0.007(wL-10%), for remoulded soil
Question: What is thixotropy?
Answer: The phenomenon of regaining of the loss of strength with the passage of time, with no change in water content, is known as thixotrophy.
Question: What is the magnitude of limiting moment of resistance for different grade of steel?
Answer: The magnitude of the limiting moment of resistance
- MU,LIM= 0.148 fckbd2 for Fe250
- MU,LIM= 0.138 fckbd2 for Fe415
- MU,LIM= 0.133 fckbd2 for Fe500
Question: What is limiting depth of neutral axis for various grade of steel?
Answer:
- XU,MAX= 0.53d ,for fe250
- XU,MAX= 0.48d ,for fe415
- XU,MAX= 0.46d ,for fe500
Question: Which clay mineral exhibit large swelling and shrinkage ?
Answer: Montmorillonite. Highest percent is found in bentonite followed by black cotton soil.
Question: What is Phreatic line?
Answer: Top flow line or seepage line through the body of the dam is phreatic line. Along phreaic line pressure head is zero. For stable slope, phreatic line should not touch the downstream slope of the dam.
Question: How will you determine hardness and toughness of aggregate?
Answer: Hardness is resistance to abrasion. Los Angle’s test is performed to know hardness. Toughness is resistance to impact and ‘Aggregate impact test is conducted.
Question: Which test is conducted using Pensky-Martin close cup and open cup?
Answer: Flash point and fire point test is conducted using the above mentioned instruments.
Question: If XU>XU,max then section is designed as?
Answer: Over-reinforced section.
Note: IS 456 : 2000 does not prefer designing a s/c as Over-reinforced section. This is so because in such section sudden failure occurs by crushing of the concrete in compression, without giving any warning of impending failure.
Question:IS 456 : 2000, what are the values of partial safety for the materials?
Answer:
- Limit State of Collapse: a) steel – 1.15 b) concrete – 1.5
- Limit State of Serviceability : a) steel – 1 b) concrete – 1
Question: Which test is preferred to determine the undrained shear strength of the soft clay ?
Answer: Vane Shear test is used to determine the un-drained shear strength of the soft clay. Note: This test is not suitable when clay contains sand or silt laminated or fissures clay.
Question: What is ‘Negative skin friction’ ?
Answer: When soil surrounding a portion of the pile settles more than pile, a downward drag occurs on the pile. This downward drag is negative ski friction. Occurs in compressible soil, soft and loose soil and recently filled up soil.
Question: For calculation of stopping sight distance (SSD) ,what are longitudinal friction coefficient recommended by IRC?
Answer: The recommended longitudinal friction coefficient by IRC is 0.35 to 0.4.
Question: In CBR test, what are the standard load corresponding to 2.5mm and 5mm penetration?
Answer: The standard loads responding the above mentioned penetration are as follows
- 2.5 mm penetration – 1370 kg
- 5 mm penetration – 2055 kg
Question: Multiplication of length of a Traverse leg to what will give you its latitude?
Answer: When a Cosine of the reduced bearing is multiplied with the length of the traverse leg we get its latitude.
Question: The line which joins two equal elevations of an earth surface is called as?
Answer: Contour Line joins the two equal elevations on an earth surface.
Question: What is the the Factor of Safety against the sliding of slope?
Answer: The factor of safety against the sliding of slope is the ratio of actual cohesion to that required to maintain stability of slope.
Question: How does the seepage force on the soil act?
Answer: The seepage force in the soil acts, proportional to the head loss, proportional to the exit gradient, perpendicular to the equipotential lines.
Question: What is the minimum diameter of the longitudinal iron bars used for construction of columns?
Answer: The minimum diameter of the longitudinal bars used for column construction is 12 mm.
Question: The base slab of a retaining wall generally thickness equal too?
Answer: The base slab of a retaining wall has thickness equal to the width of the stem at the bottom.
Question: What is the formula for calculation of the critical depth of a channel?
Answer: The formula for critical depth (h) = V x V / G.
Question: What is the ratio of maximum velocity to average velocity of viscous fluid through a circular pipe ?
Answer: The ratio of maximum velocity to average velocity of viscous fluid through a circular pipe is 2.00
Question: According to IS 456 : 2000 ,What is minimum and maximum tension reinforcement in beam?
Answer:
- Maximum area of tension reinf. (AS) shall not exceed 0.04bD (4%)
- Minimum area of tension reinf. (AS) = 0.85bd/fy (provided to prevent sudden failure)
Question: what is characteristic strength and characteristic load?
Answer: Characteristic strength is defined as the strength below which not more than 5% of the test results are expected to fall and Characteristic load is the load which has 95% probability of not being exceeding during the life span of the structure.
Question: What is difference between aqueduct, super passage and level crossing?
Answer:
- When a canal is carried over a natural drainage, the structure provided is aqueduct
- When a canal is carried below a natural drainage, the structure provided is super passage.
- When a canal and a drainage approach each other at the same level, the structure is level crossing
Question: In order to ensure smooth entry of water in a canal, what angle is kept between head regulator and water?
Answer: 110⁰
Question: Bitumen in solid , fluid and in semi-fluid state is known as?
Answer: Bitumen in
- solid state, is called asphalt
- semi fluid state, is called mineral tar
- fluid state, is called petroleum
Question: The rocks which are formed due to cooling of magma at a considerable depth from earth’s surface are called as?
Answer: Plutonic Rock
Question: What is least count of theodolite, prismatic compass and leveling staff?
Answer:
- Theodolite = 20″
- prismatic compass = 30′
- least count of leveling staff is 5mm
Question: When will you say that the intercept of a staff is minimum?
Answer: The intercept of a staff is minimum if the staff is held truly normal to the line of sight.
Question: What is criteria for hydraulically efficient section for an open channel flow ?
Answer: For a given area, slope and roughness coefficient, s/c that has least wetted perimeter is Hydraulically efficient.
This is so because, the s/c is hydraulically efficient if the maximum discharge takes place, which depend on velocity. V is prop. to hydraulic radius(R) . R= A/P. So for maximum R, P should be minimum.
Question: What is Pitot tube used for ?
Answer: It is used to measure velocity at any section of a pipe or channel. V= sq. root(2gh)
Question: For determing the specific gravity of soil solids, using a pycnometer of 500 cc., the following data is available : Weight of dry empty pycnometer = 125 g Weight of dried soil and pycnometer = 500 g Weight of dried soil and distilled = 850 g water filled in pycnometer up to top The specific gravity of soil soilds, is
Answer: 2.5.
W1= 125 g; W2= 500 g ;W3= 850g; W4 = 500g+125g= 625 g (water+ empty pycnometer)
G = (W2-W1) / (W2-W1)-(W3-W4) = 2.5
Question: What is the hydraulic gradienti, if the specific gravity and voids in soil sample areGanderespectively ?
Answer: The loss of head per unit length of flow through soil is known as hydraulic gradient(i).
i=h/l = submerged unit wt. of soil / unit wt. of water = (G-1) / (1+e)
Question: According to IS 456 : 2000, what is ultimate strain in concrete?
Answer: In bending compression – 0.0035 ( generally in beams)
In axial compression – 0.002 ( generally in column )
Question: Total pressure on the vertical face of a retaining wall of height h acts parallel to free surface and from the base at a distance of ?
Answer: h/3. Pressure distribution on the vertical face of the wall is triangular and hence total pressure acts through the centroid of the triangle.
Question: In plastic analysis, what is shape factor of a section?
Answer: Shape factor is defined s the ratio of fully plastic moment of the section to the yielding moment of the section. (S=MP/MY or ZP/ZY). For a ductile material like structural steel, a member reaching yield at the extreme fibred retains a reserve strength that varies with shape factor . S for rectangular s/c = 1.5, for circular s/c =1.7, for diamond= 2 ,for triangular s/c = 2.34.
Question: What is shear stress at principal planes?
Answer: zero. Principal planes are the planes carrying maximum direct stress and zero shear stress.
Question: What are the test essential for quality control of Portland cement ?
Answer:
- setting time test
- soundness test
- tensile strength test
- consistency test
Question: What is PPC?
Answer: Possolana portland cement (PPC) uses siliceous material (Pozzolana), which possesses cementetious properties in the presence of cement. Fly ash, blast furnace slag, silica fumes are used as pozzolana. Reduction in cost, increase in workability, less heat of hydration, resistance to the aggressive environment are its advantages.
Question: What does the close contour of increasing values towards centre represent?
Answer: It represent a hill. Increasing values of contour towards centre indicates that R.L is increasing. If the values of contour is decreasing toward centre then it represent a depression.
Question: According to Transit Rule, what is the correction for a side whose latitude is L ,arithmetic sum of latitudes of a closed traverse is ∑L and closing error in latitude is dx ?
Answer:
(L * dx) / ∑
L
Question: What is relation between Gauge pressure, absolute pressure and atmospheric pressure ?
Answer: Gauge pressure = absolute pressure – atmospheric pressure
Gauge pressure is calculated considering atmospheric pressure as datum whereas datum is considered as zero while calculating absolute pressure.
Question: Why do we use mercury in barometer instead of water?
Answer: Atmospheric pressure is 76 cm of mercury but if we represent it in terms of water, the atmospheric pressure comes to be 10 m of water. Hence the height of the barometer will be very high if we used water instead of mercury. Moreover, vapor pressure of mercury is practically zero.
Question: What is composite beam and compound beam?
Answer: Beams composed of more than one material, rigidly connected together so as to behave as one piece is known as composite beam. Crossection of composite beam is made of one or more material. Compound beam is made of one or more material along the length.
Question: What is the maximum magnitude of shear stress due to shear force F on a rectangular section of area A ?
Answer: 3F/2A . Maximum shear stress in a rectangular section is 1.5 times average shear stress (F/A) and it occurs at neutral axis.
Question: The imaginary line joining the points of equal elevation on the surface of the earth is called as ?
Answer: Contour lines. This is what is done in block contouring, point with equal elevation is joined to form contour if that elevation.
Question: S is the length of a sub chord and R is the radius of simple curve, the angle of deflection between its tangent and sub-chord, in minutes, is given by ?
Answer: Angle of deflection = 1718.9 S/R
Question: What is the maximum shear stress of a triangular section having base b, height h, which placed with its base horizontal? Where does it occur?
Answer: For a triangular section maximum shear stress does not occur at N.A , it is maximum at height h/2 from base with magnitude of 1.5 avg. shear stress and at N.A it is 1.33 avg. shear stress.
Question: The deflection due to couple M at the free end of a cantilever of length L is?
Answer: ML2/2EI (castiglianos theorem can be used to derive it )
Question: What is the mechanism of cavitations in pipe?
Answer: If pressure at any point in the pipe becomes equal to vapors pressure (pressure at which liquid boils), vaporization of liquid starts and formation of bubbles takes place. These bubbles are carried into region of high pressure, where they collapse giving rise to high impact pressure. This cause materials from adjoining to erode and cavities are formed.
Question: What is Froude number?
Answer: It is defined as the square root of ratio of inertial force by gravitational force. For a critical flow in open channel Froude number is one.
Question: What are the minimum number of bars to be used in RCC column?
Answer:
- For rectangular column – 4
- For circular column – 6
- For octagonal column – 8
Question: What is the minimum diameter of the longitudinal bar in column?
Answer: According to IS 456 : 2000 , Minimum Diameter of bar should be 12mm.
Question: Why is it required to apply dilatancy correction?
Answer: Silty fine sand and fine sand below the water table develops pore water pressure which increases the resistance offered by the soil and hence increases the penetration number. to compensate this dilatancy correction is applied. Nr= 15+ (N0+15)/2 ; N0 is the corrected SPT value obtained after applying overburden correction.
Question: What is ‘degree of consolidation’ ?
Answer: It is the ratio of settlement at any time (t) to the final settlement.
Question: If a particle moves along a straight line such that its equation of motion is given as x=t3 – 3t2+ 15, then what is the ratio of the acceleration after 9 sec and 5 sec?
Answer:
- dx/dt = v (velocity) and dv/dt = A (acceleration); Hence d2x/dt2 = A = 6(t-1)
- at t=9; A= 48 AND at t=5; A=24 and ratio of both is 2
Question: What is the unit of Force, Work and Power?
Answer:
- Force = Newton (N)
- Work = Force * Displacement = N.m = Joule
- Power= Work / time = N.m/sec = Joule/ sec = watt. (1 H.P =746 watts)
Question: Difference between tor steel , tmt bar and tmx bars ?
Answer: Twisting operation is not involved in the production of Thermo Mechanically Treated steel bars (TMT), so no residual stresses are involved in that, which in turns reduces corrosion resistance. High corrosion resistance TMT (HCRM) are specially meant for use in coastal environment. Thermex technology is used in TMX bars. It is high quality TMT bar. Thermex bar has a proven record resisting loss of strength at high temperature as experienced during fire.
Question: Why steel stirrups in the column have more spacing at the centre and less spacing at the ends?
Answer: Steel stirrups are provided to resist the shear , and shear fore is more at ends.
Question: What is the Degree of saturation of a natural soil deposit having water content 10%, specific gravity 2.50 and void ratio 0.55 ?
Answer:relation : S*e = G*w
S = G*w/e = 2.5 * 10 / 0.55 = 45.45%
Question: What is the difference between the porosity and the void ratio ?
Answer: Void ratio is the ratio of volume of void to volume of solid whereas porosity is defined as volume of voids to total volume of the soil.
Question: What is the ratio of strengths of solid to hollow shafts, both having outside diameterDand hollow having inside diameter D/2, in torsion ?
Answer: 16/15 – Strength is directly proportional to section modulus (Z). Z for solid shaft = Π*D3/16. Z for hollow shaft = Π (D4– (D/2)4) / (16*D)
Question: What is bending moment at the section if the shear force along a section of a beam is zero?
Answer: Maximum. dM/dX = shear force ; if S.F = 0 then dM/dX=0 i.e. bending moment is maximum
it can also be noted from above relation that the slope of bending moment diagram gives shear force.
Question: What is the section modulus of a rectangular bar of width b and height d is being used as a cantilever? The loading is in a plane parallel to the side b.
Answer: b2d/6 . Section modulus = I / Y . I is about the axis perpendicular to the plane of loading i.e along axis parallel to side d and hence I=b3d/12 and Y is (b/2)
Question: What is point of contraflexure in a loaded beam?
Answer: The point of contraflexure is the point where bending moment is zero or bending moment changes its sign
Question: What are the assumption in the theory of bending f the beam?
Answer: Material is homogeneous and isotropic. Young’s modulus is same in tension and in compression and each layer is independent to expand and contract
Question: The maximum deflection and maximum rotation due to a uniformly distributed loadw/unit length over entire span of a cantilever of lengthl and of flexural rigidly EI, is ?
Answer: Maximum deflection is (Wl4/8EI) and maximum rotation is (Wl3/6EI). Moment area method, castiaglano’s theorem and column analogy theorem can be used to derive above values.
Question: What are the composition of various grade of concrete?
Answer:
- M10 = 1:3:6
- M15 = 1:2:4
- M20 = 1:1.5:3
- M25 = 1:1:2
For M30, M40 mix design is followed
Questions: What is the work-ability of the concrete with compaction factor of 0.95?
Answer:
- vey low workability – 0.78
- low workability – 0.85
- medium workability – 0.92
- high workability – 0.95
Question: What is the maximum negative pressure that can develop in siphon?
Answer: In practice, if the pressure in the siphon is reduced to about 7.8 m of water vacuum, the dissolved air and other gases, would come out of the solution and get collected at the summit of the siphon in sufficient quantity to form a air lock, which will obstruct the continuity of flow ( flow will stop).
Question: what are the property of steam function ψ ?
Answer:
- ψ is constant everywhere on any stream line
- the difference of stream functions for two stream line is equal to the flow rate between them.
- If ψ exist then it is possible case of fluid flow which may be rotational or irrotational.
- it ψ satisfies laplace equation the flow is irrotational.
Question: What tare he assumption of the Bernoulli’s equation
Answer:
- fluid is non-viscous
- fluid is homogenous
- fluid is steady
- fluid is along stream line
Question: According to IS 456, what is the minimum grade of concrete to be used in RCC structure?
Answer: According to the IS 456 : 2000 (refer table no. 3 and 5)
Question: What is the effective width of a Column Strip of a Flat Slab?
Answer: The effective width of a column strip of a flat slab is equal half the width of the panel.
Question: The minimum water content at which the soil just begins to crumble when rolled into threads 3 mm in diameter, is known?
Answer: It is the test to determine plastic limit of soil sample
seepage of water through soils (Q) = K x I x A
where K = coefficient of permeability of soil i = h/l
Question: If the atmospheric pressure on the surface of an oil tank (sp. gr. 0.8) is 0.1 kg/cm2, the pressure at a depth of 2.5 m, is?
Answer: 3 meter of water
pressure due to atm = 0.1 * 104 * 10 KN/M2 ( g = 10 m/s2 )
pressure due to oil = h * density * g = 2.5 * 800 * 10 = 2 * 104 KN/M2
pressure head = total pressure / (density of water * g)
Question: what is the Unit of kinematic viscosity ?
Answer: SI : m2/s
CGS : cm2/s (note: cm2/s is also known as stokes)
Question: What is standard consistency of cement? how will you determine it?
Answer: Standard consistency of cement is the percentage of the water required to make a workable cement paste. As per vicat’s test ” the percentage of the water added to the cement at which the needle cannot penetrate 5 to 7 mm from bottom of the mould”
Question: The final strength of concrete is due to?
Answer: Dicalcium silicate imparts final strength to the concrete. Tricalcium silicate gives early strength and evolves more heat of hydration of about 120cal/g whereas dicalcium silicate gives later strength (it evolves less heat, around 60cal/g) . Tri-calcium Aluminate gives initial strength but evolves very high heat of hydration of about 320 cal/g.
Question: What is the difference between normally consolidated and over consolidated clay?
Answer: A normally consolidated soil is one which has not been subjected to a pressure greater than the present existing pressure whereas a soil is said to be over consolidated if, in past, it had been subjected to a pressure greater than the present existing pressure.
Question: The minimum water content at which the soil retains its liquid state and also possesses a small shearing strength against flowing, is known as?
Answer: Liquid limit. liquid limit is the state at which the soil is in liquid state but still posses a small shear strength of about 2.7 kn/m2
Question: What is the name of the binding materials used in Mortar?
Answer: Cement is used as the binding material. Cement when mixed with proper amount of water develops an adhesive [sticky mixture]. This adhesive property of cement is used for binding effect, the effect that holds material together.
Question: Why Granite is called a polymineralic rock?
Answer: Granite is an igneous rock. The reason it is called as polymineralic rock because, granite is a mixture of Feldspar, Quartz, Mica and Amphibole minerals. Granite is used in various architectural construction work due to its good display and strength.
Question: What is a Raymond Pile?
Answer: A Raymond pile is a step taper pile which is triangular shape with its tip towards the ground surface. Raymond piles are mainly used because they have a high load bearing capacity.
Question: What is Dado and what is its primary use?
Answer: Dado is the lower part of the wall room usually decorated with tiles. Dado is primarily used in bathrooms and sanitation places. As the large usage of water in bathrooms might cause damage to the bathroom walls and paint.
Questions: What is the use of Hydrographic Surveys?
Answer: Hydrographic surveys are used to map large water bodies present beneath and above the ground water surfaces. Thus the location of usable water can be easily located for various uses.
Questions: In surveying what curve joins two Gradients?
Answers: Parabolic curves joins two gradients in a survey.
i hope this answers wud provide n intense help to my civil engineering fellow frnds....
Simple Beam – Concentrated Load at Centre
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Simple Beam – Concentrated Load at Any Point