Unit - 3
63. Yielding of steel in singly reinforced beam occurs in
a. under-reinforced beam
b. over reinforced beam
c. balanced reinforced beam
d. none of these
64. In under reinforced singly reinforced beam, concrete crushes at its maximum strain i.e.,
a. 4.75 %
b. 1.25 %
c. 5.20 %
d. 0.35 %
65. Commonly adopted moisture tension, in atmosphere, of soil at permanent wilting point is
a. 16
b. 18
c. 60
d. 15
66. The ratio of the limiting value of the depth of neutral axis and the depth of the section of a singly reinforced beam is equal to:
a. 0.0045
b. 0.0055
c. 0.0035
d. None
67. The characteristic strength of steel is defined as the value of the strength of 3teel below which not more than 5% of the test results fail.
a. True
b. False
68. The depth of neutral axis of singly reinforced beam
a. remains unaffected the change of characteristic strength of steel
b. increases with the increases of characteristic strength of steel
c. decreases with the increases of characteristic strength of steel
d. All of above
69. The characteristic strength (aK) of concrete is usually referred to
a. 7 days cube strength
b. 21 days cube strength
c. 28 days cube strength
d. None of above
a. True
b. False
71. The depth of neutral axis of a singly reinforced beam from the extreme compression fibre is:
a. 0.133 ack bd2
b. 0.135 cot bd2
c. 0.138 ack bd2
d. 0.149 ad, bd2
72. The depth of neutral axis of a section 200 mm x 300 mm reinforced and 3 bars each of 20 mm diameter in tension and having characteristic strength of concrete and steel 15 Nimm2 and 250 Nimm2 respectively, is 159 mm.
a. True
b. False
73. The limiting moment of resistance for a singly reinforced beam using Fe 250 steel and general grade concrete, is
a. 2.417 ayb
b. 2.417ck cry At
c. 2.417 ack At
d. 2.417 ay At
a. Limit state theory
b. Working stress theory
c. Ultimate stress theory
d. All of above
75. The aspect ratio is defined as the ratio of
a. length to breadth of a state
b. effective width of flange and effective depth of the beam
c. width of well and depth of flange
d. None of above
76. The dowel force is the shear force
a. at the bottom of the beam
b. at the top of the beam
c. across the neutral axis
d. across the steel bars
77. To ensure that under the applied moment the concrete and steel in singly reinforced beam reach their stresses, the minimum area of steel where bd is the effective compression area and CSy is the characteristic
a. 0.42 bd
b. 0.36 ?bd
c. 0.85 ?bd
d. 0.87 bd
78. For a rectangular simply supported beam for 4.5 m effective span, based on the code restriction, the depth is :
a. 255 mm
b. 222 mm
c. 225 mm
d. None of above
a. double the tension reinforcement
b. greater than the tension reinforcement
c. (c) lower than the tension reinforcement
d. equal to that of tension reinforcement
80. The design of a doubly reinforcement beam section involves the determination of :
a. depth of the section
b. area of tension reinforcement
c. breadth of no section
d. none of these
81. The strain at the level of compression reinforcement is doubly reinforced beam is, where d' is the effective cover in compression reinforcement and Xm is the maximum depth of the neutral axis is 0.0035 (1 ? Xm d' ).
a. False
b. True
82. In doubly reinforced beams, the percentage of the maximum compression reinforcement of the gross cross-sectional area of beam should not exceed:ack At where ay and act, are the characteristic strength of steel and concrete respectively and At is the area of tension steel
a. 7%
b. 6%
c. 5%
d. 4%
83. The slab forming the top part of flanged beam mid span
a. less than the width of the rib
b. equal to the width of the rib
c. greater than the width of the rib
d. equal to the perimeter of effective rectangular of the section
84. At continuous supports, the lower portion of the slab is in compression.
a. False
b. True
85. The intermediate beams between several beams case monolithically with the slab act as L-beams.
a. False
b. True
86. The intermediate beams between several beams case monolithically with the slab act as T-beams.
a. True
b. False
87. The aspect ratio of slab is:
a. None of mentioned
b. the ratio of superimposed load and the self weight
c. the ratio of length to breadth
d. the ratio of length to breadth
a. Span250
b. Span200
c. Span100
d. Span120
89. The criterion of vertical deflection is satisfied for cantilever for spans up to 10 m if span to depth ratio is not greater than 7.
a. False
b. True
90. The deflection of a structure designed by limit state method, due to all loads including the effects of temperature, creep and shrinkage below the as-cast level of the supports of roofs, floors and all other horizontal members should not normally exceed the lesser value
a. span350 or 20mm
b. span250 or 20mm
c. span200 or 15mm
d. span 300 or 25 m m
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