225. Cracking moment in a singly reinforced concrete beam is equal to where Cr = 0.7 I7 yt = distance of extreme tension fibre from the neutral axis:

A. cscrlg

B. YcrIg yt

C. acr

D. 2c7

226. At a given loading of a singly reinforced beam,

A. strains in steel and concrete are equal

B. strains in steel and concrete are in proportion to their moduli of elasticity

C. stresses in steel and concrete are in inverse proportion of their moduli of elasticity

D. none of these

227. The analysis and design of reinforced concrete beam at the cracked concrete stage is done by

A. working stress design method

B. ultimate stress design method

C. limit state stress design method

D. all the above methods

228. Failure of a reinforced concrete beam occurs as soon as the concrete strain in compression reaches:

A.0.0025

B.0.003

C.0.0035

D.0.004

229. Pick up the correct statement from the following

A. At limit state of collapse, the residing moment on the section provided by the internal forces, is called the ultimate moment by resistance

B. The entire section of the beam at limit state of collapse, above the neutral axis remains in compression

C. The entire section of the beam at limit state of collapse, below the neutral axis remains intension and the concrete gets cracked

D. All of these

230. The ratio of the depth of the parabolic and rectangular portion block at the limit state of collapse of a singly reinforced section is

A. 1 : 2

B. 4 : 3

C. 3 : 4

D. 4 : 5

231. The ratio of the force of compression in the parabolic stress block and their in rectangular stress block of a reinforced concrete beam at limit state collapse of a reinforced concrete beam at limit state collapse, is

A.0.8885

B.0.8886

C.0.8887

D.0.8883

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