Rcc Structures Design Set 6 MCQs

Q1 | The diameter of main bars in R.C.C. columns, shall not be less than

6 mm

8 mm

10 mm

12 mm

Q2 | If d is the diameter of a bar, ft is allowable tensile stress and fb, is allowable bondstress, the bond length is given by

ft.d/4fb

( /4). (ft.d/fb)

ft.d²/fb

( /4). (ft.d3/fb)

Q3 | An intermediate T-beam reinforced with two layers of tensile steel with clear cover 13 cm encasted with the floor of a hall 12 metres by 7 metres, is spaced at 3 metres from adjoining beams and if the width of the beam is 20 cm, the breadth of the flange is

300 cm

233 cm

176 cm

236 cm

Q4 | The length of lap in tension reinforcement should not be less than the bar diameter × (actual tension / four times the permissible average bond stress) if it is more than

18 bardiameters

24 bardiameters

30 bardiameters

36 bardiameters

Q5 | As the percentage of steel increases

Depth of neutral axis decreases

Depth of neutral axis increases

Lever arm increases

Lever armdecreases

Q6 | The effective width of a column strip of a flat slab, is

One-fourth the width of the panel

Half the width of the panel

Radius of the column

Diameter ofthe column

Q7 | As per IS : 1343, total shrinkage for a pre-tensioned beam, is

3.0 × 10-2

3.0 × 10-3

3.0 × 10-5

3.5 × 10-5

Q8 | Dimensions of a beam need be changed if the shear stress is more than

10 kg/cm2

15 kg/cm2

20 kg/cm2

25 kg/cm2

Q9 | Based on punching shear consideration, the overall depth of a combined footing under a column A, is

(Area of the column A × Safe punching stress)/Load on column A

(Perimeter of column A × Safe punching stress)/(Load on column A + Upward pressure × Area of the column)

(Perimeter of column A × Safe punching stress)/(Load on column A × Upward pressure × Area of the column)

None of these

Q10 | Pick up the correct statement from the following:

A pile is a slender member which transfersthe load through its lower end on a strong strata

A pile is a slender member which transfers its load to the surrounding soil

A pile is a slender member which transfers its load by friction

A pile is a cylindrical body of concrete which transfersthe load at a depth greater than its width

Q11 | In a combined footing if shear stress exceeds 5 kg/cm2 , the nominal stirrups provided are:

6 legged

8 legged

10 legged

12 legged

Q12 | The weight of reinforced concrete, is generally taken as

2200 kg/m3

2300 kg/m3

2400 kg/m3

2500 kg/m3

Q13 | If W is the load on a circular slab of radius R, the maximum circumferential momentat the centre of the slab, is

WR²/16

2WR²/16

3WR²/16

Zero

Q14 | If is weight of a retainingwall and is the horizontal earth pressure, the factor of safety against sliding, is

1

1.25

1.5

2

Q15 | The effective span of a simply supported slab, is

Distance between the centres of thebearings

Clear distance between the inner faces of the walls plus twice the thickness of the wall

Clear span plus effective depth of the slab

None of these

Q16 | In a beam the local bond stress Sb, is equal to

Shearforce/(Leaver arm× Total perimeter ofreinforcement)

Total perimeter ofreinforcement/(Leaver arm × Shearforce)

Leaver arm/(Shearforce × Total perimeter ofreinforcement)

Leaver arm/(Bendingmoment × Total perimeter ofreinforcement)

Q17 | A continuous beam shall be deemed to be a deep beam if the ratio of effective span to overall depth, is

2.5

2

Less than 2

Less than 2.5

Q18 | With usual notations the depth of the neutral axis of a balanced section, is given by

mc/t = (d -n)/n

t/mc = (d -n)/n

t/mc = (d + n)/n

mc/t = n/(d - n)

Q19 | Pick up the true statement from the following:

Plain ceiling provides the best property diffusing light

In the absence of beams, it is easier to installpiping

In the absence of beams, it is easier topaint

All the above

Q20 | If the maximum shear stress at the end of a simply supported R.C.C. beam of 16 m effective span is 10 kg/cm2 , the length of the beam having nominal reinforcement, is

8 cm

6 m

8 m

10 m

Q21 | If the length of a wall on either side of a lintel opening is at least half of its effective span L, the load W carried by the lintel is equivalent to the weight of brickwork contained in an equilateral triangle, producing a maximum bending moment

WL/2

WL/4

WL/6

WL/8

Q22 | The section of a reinforced beam where most distant concrete fibre in compression and tension in steel attains permissible stresses simultaneously, is called

Balanced section

Economic section

Critical section

All the above

Q23 | The length of the lap in a compression member is kept greater than bar diameter x (Permissible stress in bar / Five times the bond stress) or

12 bardiameters

18 bardiameters

24 bardiameters

30 bardiameters

Q24 | The system in which high tensile alloy steel bars (silica manganese steel) are used as prestressing tendons, is known as

Freyssinet system

Magnel-Blaton system

C.C.L. standardsystem

Lee-McCallsystem

Q25 | An under-reinforced section means

Steel is provided at the underside only

Steel provided is insufficient

Steel provided on one face only

Steel will yieldfirst