148.  In case the factor of safety against sliding is less than 1.5, a portion of slab is constructed downwards at the end of the heel slab, which is known as
A. a key
B. a cut-off wall
C. a rib
D. all the above.

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149. The stem of a cantilever retaining wall which retains earth level with top is 6 m. If the angle of repose and weight of the soil per cubic metre are 30? and 2000 kg respectively, the effective width of the stem at the bottom, is
A.51.5
B.52.5
C.53.5
D.54.5

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150. In a cantilever retaining wall without a heel slab
A. thickness of the stem is kept same throughout
B. base slab is made 10 cm thicker than the stem
C. width of the base slab is kept 0.7 time the total height of the wall
D. all the above.

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151.  The horizontal portion of a step in a stairs case, is known as
A. rise
B. flight
C. winder
D. tread.

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152. A very comfortable type of stairs is
A. straight
B. dog legged
C. geometrical
D. open newel.

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153.  If T and R are tread and rise respectively of a stair, then
A. 2R + T 60
B. R + 2T = 60
C. 2R + T 30
D. R + 2T = 30

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154. The minimum head room over a stair must be
A. 200 cm
B. 205 cm
C. 210 cm
D. 200 cm

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