If the tendon is placed at an eccentricity e below the centroidal axis of the longitudinal axis of a rectangular beam (sectional modulus Z and stressed load P in tendon) the stress at the extreme top edge

A Is increased by $$\frac{{{\text{PZ}}}}{{\text{e}}}$$
B Is increased by $$\frac{{{\text{Pe}}}}{{\text{Z}}}$$
C Is decreased by $$\frac{{{\text{Pe}}}}{{\text{Z}}}$$
D Remains unchanged

Correct Answer: Is decreased by $$\frac{{{\text{Pe}}}}{{\text{Z}}}$$

Bissoy MCQ
#Civil Engineering #RCC Structures Design

Related Questions

If ‘A’ is the sectional area of a pre-stressed rectangular beam provided with a tendon pre-stressed by a force ‘P’ through its centroidal longitudinal axis, the compressive stress in concrete, is
A $$\frac{{\text{P}}}{{\text{A}}}$$
B $$\frac{{\text{A}}}{{\text{P}}}$$
C $$\frac{{\text{P}}}{{2{\text{A}}}}$$
D $$\frac{{2{\text{A}}}}{{\text{P}}}$$
‘P’ is the pre-stressed force applied to tendon of a rectangular pre-stressed beam whose area of cross section is ‘A’ and sectional modulus is ‘Z’. The minimum stress ‘f’ on the beam subjected to a maximum bending moment ‘M’ is
A $${\text{f}} = \frac{{\text{P}}}{{\text{A}}} - \frac{{\text{Z}}}{{\text{M}}}$$
B $${\text{f}} = \frac{{\text{A}}}{{\text{P}}} - \frac{{\text{M}}}{{\text{Z}}}$$
C $${\text{f}} = \frac{{\text{P}}}{{\text{A}}} - \frac{{\text{M}}}{{\text{Z}}}$$
D $${\text{f}} = \frac{{\text{P}}}{{\text{A}}} - \frac{{\text{M}}}{{6{\text{Z}}}}$$
‘P’ is the pre-stressed force applied to the tendon of a rectangular pre-stressed beam whose area of cross section is ‘A’ and sectional modulus is ‘Z’. The maximum stress ‘f’ in the beam, subjected to a maximum bending moment ‘M’, is
A $${\text{f}} = \frac{{\text{P}}}{{\text{A}}} - \frac{{\text{Z}}}{{\text{M}}}$$
B $${\text{f}} = \frac{{\text{A}}}{{\text{P}}} - \frac{{\text{M}}}{{\text{Z}}}$$
C $${\text{f}} = \frac{{\text{P}}}{{\text{A}}} - \frac{{\text{M}}}{{\text{Z}}}$$
D $${\text{f}} = \frac{{\text{P}}}{{\text{A}}} - \frac{{\text{M}}}{{6{\text{Z}}}}$$
If the loading on a pre-stressed rectangular beam, is uniformly distributed, the tendon to be provided should be.
A Straight below centroidal axis
B Parabolic with convexity downward
C Parabolic with convexity upward
D Straight above centroidal axis
If the maximum dip of a parabolic tendon carrying tension P is h and the effective length of the pre-stressed beam is L, the upward uniform pressure will be
A $$\frac{{8{\text{hP}}}}{l}$$
B $$\frac{{8{\text{hP}}}}{{{l^2}}}$$
C $$\frac{{8{\text{h}}l}}{{\text{P}}}$$
D $$\frac{{8{\text{h}}l}}{{{{\text{P}}^2}}}$$
The ratio of maximum shear stress developed in a rectangular beam and a circular beam of the same cross-sectional area is
A $$\frac{2}{3}$$
B $$\frac{3}{4}$$
C 1
D $$\frac{9}{8}$$
The rectangular beam 'A' has length ‘l’, width ‘b’ and depth ‘d’. Another beam 'B' has the same length and depth but width is double that of 'A'. The elastic strength of beam 'B' will be _________ as compared to beam ‘A’.
A Same
B Double
C Four times
D Six times
The rectangular beam 'A ' has length l, width b and depth d. Another beam 'B' has the same width and depth but length is double that of 'A'. The elastic strength of beam 'B' will be __________ as compared to beam A.
A Same
B One-half
C One-fourth
D One-eighth
The rectangular beam 'A' has length l, width b and depth d. Another beam 'B' has the same length and width but depth is double that of 'A'. The elastic strength of beam B will be __________ as compared to beam A.
A Same
B Double
C Four times
D Six times
The simply supported beam 'A' of length '$$l$$' carries a central point load 'W'. Another beam 'B' is loaded with a uniformly distributed load such that the total load on the beam is 'W'. The ratio of maximum deflections between beams 'A' and 'B' is
A $$\frac{5}{8}$$
B $$\frac{8}{5}$$
C $$\frac{5}{4}$$
D $$\frac{4}{5}$$

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