Test 3 - RCC Beam Design by Working Stress Method

Question 1 ప్రశ్న 1

In the Working Stress Method analysis of an ordinary cracked singly reinforced rectangular beam, which set of assumptions is appropriate?

A Plane sections remain plane, tensile concrete is neglected, and steel and concrete are treated elastically under working loads. B Plane sections do not remain plane, tensile concrete carries all tension, and steel is assumed perfectly plastic. C Concrete tension and steel tension are assumed numerically equal at every level. D The neutral axis is always fixed at half the effective depth regardless of reinforcement.

Question 2 ప్రశ్న 2

What is the principal purpose of transforming the tensile reinforcement into an equivalent concrete area in Working Stress beam analysis?

A To permit an elastic composite section containing two materials to be analysed using one reference material B To convert the steel permanently into concrete for construction purposes C To eliminate the need for strain compatibility D To make the neutral axis independent of reinforcement area

Question 3 ప్రశ్న 3

For a singly reinforced rectangular beam of width b, effective depth d, tensile reinforcement Ast and modular ratio m, with tensile concrete neglected, which equation determines the neutral-axis depth x from the compression face?

A bx²/2 = mAst(d - x) B bxd = mAstx C bx² = Ast(d + x) D bd²/2 = mAstx

Question 4 ప్రశ్న 4

For a cracked singly reinforced beam transformed to equivalent concrete, how is the tensile reinforcement area Ast represented?

A Ast/m B (m - 1)Ast C mAst D m²Ast

Question 5 ప్రశ్న 5

A singly reinforced rectangular beam has b = 300 mm, d = 500 mm, Ast = 600 mm² and modular ratio m = 13.33. Using bx²/2 = mAst(d - x), what is the neutral-axis depth approximately?

A 104 mm B 139 mm C 184 mm D 250 mm

Question 6 ప్రశ్న 6

For the beam in the previous question, what is the moment of inertia of the cracked transformed section about its neutral axis approximately? Use I = bx³/3 + mAst(d - x)².

A 0.66 × 10^9 mm⁴ B 1.31 × 10^9 mm⁴ C 2.22 × 10^9 mm⁴ D 3.28 × 10^9 mm⁴

Question 7 ప్రశ్న 7

The beam with b = 300 mm, d = 500 mm, Ast = 600 mm² and m = 13.33 is subjected to a working bending moment of 50 kN·m. Using x = 138.8 mm and I = 1.311 × 10^9 mm⁴, what are the extreme concrete compressive stress and tensile-steel stress approximately?

A Concrete = 5.29 N/mm² and steel = 184 N/mm² B Concrete = 7.00 N/mm² and steel = 230 N/mm² C Concrete = 4.14 N/mm² and steel = 95 N/mm² D Concrete = 10.0 N/mm² and steel = 140 N/mm²

Question 8 ప్రశ్న 8

For M20 concrete and Fe415 reinforcement, take permissible stresses σcbc = 7 N/mm² and σst = 230 N/mm². What conclusion follows for the beam in the previous question under a 50 kN·m working moment?

A Both concrete and steel stresses are within their permissible values. B Concrete exceeds its permissible stress but steel does not. C Steel exceeds its permissible stress but concrete does not. D Both materials exceed their permissible stresses.

Question 9 ప్రశ్న 9

For a balanced M20-Fe415 singly reinforced rectangular section, take σcbc = 7 N/mm², σst = 230 N/mm² and m = 13.33. What is the balanced neutral-axis factor k = x/d approximately?

A 0.189 B 0.289 C 0.389 D 0.500

Question 10 ప్రశ్న 10

For the balanced M20-Fe415 section in the previous question, what is the lever-arm factor j = 1 - k/3 approximately?

A 0.711 B 0.808 C 0.904 D 0.963

Question 11 ప్రశ్న 11

For a balanced M20-Fe415 rectangular beam with b = 300 mm and d = 500 mm, what tensile reinforcement area is required approximately?

A 440 mm² B 659 mm² C 900 mm² D 1200 mm²

Question 12 ప్రశ్న 12

What is the balanced moment of resistance of an M20-Fe415 rectangular beam having b = 300 mm and d = 500 mm under the Working Stress Method?

A 52.6 kN·m B 62.6 kN·m C 68.5 kN·m D 84.6 kN·m

Question 13 ప్రశ్న 13

For a balanced M20-Fe415 rectangular section, what effective depth is required approximately to resist a working bending moment of 100 kN·m if b = 300 mm and the balanced moment coefficient Q = 0.913 N/mm²?

A 450 mm B 500 mm C 604 mm D 750 mm

Question 14 ప్రశ్న 14

Compared with a balanced singly reinforced beam section under the Working Stress Method, an under-reinforced section generally has:

A Less tensile steel and a shallower neutral axis, with tensile-steel permissible stress governing first B More tensile steel and a deeper neutral axis, with concrete compression governing first C Exactly the balanced steel area but a lower concrete grade D No neutral axis because tensile concrete is neglected

Question 15 ప్రశ్న 15

Compared with a balanced singly reinforced beam section under the Working Stress Method, an over-reinforced section generally has:

A Less tensile steel and steel stress governing first B More tensile steel and a deeper neutral axis, with concrete permissible compression governing first C No compression zone D A neutral axis outside the concrete section

Question 16 ప్రశ్న 16

A rectangular beam has b = 300 mm, d = 500 mm, Ast = 600 mm², m = 13.33, σcbc = 7 N/mm² and σst = 230 N/mm². Its neutral-axis depth is 138.8 mm and lever arm is 453.7 mm. Which permissible-stress condition governs its Working Stress moment capacity?

A Concrete compression, giving approximately 66.1 kN·m B Steel tension, giving approximately 62.6 kN·m C Both govern exactly at 68.5 kN·m D Neither material controls because the section is uncracked

Question 17 ప్రశ్న 17

A rectangular M20-Fe415 beam has b = 300 mm, d = 500 mm and Ast = 900 mm². Using m = 13.33, its neutral axis is approximately 164.0 mm. Which Working Stress moment capacity governs?

A Steel-controlled capacity of approximately 52.6 kN·m B Concrete-controlled capacity of approximately 76.7 kN·m C Balanced capacity of exactly 68.5 kN·m D Steel-controlled capacity of approximately 92.2 kN·m

Question 18 ప్రశ్న 18

A rectangular M20-Fe415 beam has b = 300 mm, d = 500 mm and Ast = 500 mm². Using m = 13.33, its neutral-axis depth is approximately 128.5 mm. What is its Working Stress moment capacity approximately?

A 42.4 kN·m B 52.6 kN·m C 61.7 kN·m D 68.5 kN·m

Question 19 ప్రశ్న 19

A rectangular beam of b = 300 mm and d = 500 mm is to resist a working bending moment of 50 kN·m using M20 concrete and Fe415 steel. Take m = 13.33 and assume an under-reinforced design in which steel reaches its permissible stress of 230 N/mm². The compatible required tensile reinforcement area is approximately:

A 350 mm² B 475 mm² C 659 mm² D 900 mm²

Question 20 ప్రశ్న 20

For an elastic cracked singly reinforced section, which expression correctly relates tensile-steel stress σst to the extreme concrete compressive stress σc, neutral-axis depth x, effective depth d and modular ratio m?

A σst = mσc(d - x)/x B σst = σcx/[m(d - x)] C σst = mσcx/(d - x) D σst = σc/m

Question 21 ప్రశ్న 21

For a cracked beam with d = 500 mm, x = 150 mm and m = 13.33, if the extreme concrete compressive stress is 7 N/mm², what tensile-steel stress is developed approximately?

A 93 N/mm² B 150 N/mm² C 218 N/mm² D 280 N/mm²

Question 22 ప్రశ్న 22

For a cracked M20-Fe415 beam with d = 500 mm, x = 150 mm and m = 13.33, suppose the tensile steel reaches its permissible stress of 230 N/mm². What extreme concrete compressive stress would correspond to this condition approximately?

A 5.29 N/mm² B 6.35 N/mm² C 7.39 N/mm² D 10.0 N/mm²

Question 23 ప్రశ్న 23

If the applied working bending moment on a cracked RCC beam is increased from M to 1.25M without any change in section properties or cracking state, what happens to the elastic concrete and steel stresses under Working Stress analysis?

A Both stresses increase by approximately 25 percent. B Concrete stress increases by 25 percent but steel stress is unchanged. C Steel stress doubles while concrete stress is unchanged. D Both stresses decrease because the neutral axis automatically moves to mid-depth.

Question 24 ప్రశ్న 24

For the same beam dimensions, concrete grade, steel grade and modular ratio, what is the general effect of increasing the tensile reinforcement area Ast on the neutral-axis depth of a cracked singly reinforced section?

A The neutral axis generally moves deeper from the compression face. B The neutral axis always moves toward the compression face. C The neutral axis remains unchanged because only concrete determines it. D The neutral axis immediately moves outside the beam.

Question 25 ప్రశ్న 25

Consider the following statements about singly reinforced beam design by the Working Stress Method:
1. Tensile concrete is normally neglected in cracked flexural analysis.
2. A balanced section reaches permissible concrete compression and permissible steel tension simultaneously.
3. For an under-reinforced section, the tensile-steel permissible stress normally governs before concrete reaches its permissible compression stress.
4. Increasing tensile reinforcement indefinitely always increases usable Working Stress moment capacity in direct proportion to Ast without any concrete-stress limitation.

Which statements are correct?

A 1 and 4 only B 1, 2 and 3 only C 2, 3 and 4 only D 1, 2, 3 and 4

Question 26 ప్రశ్న 26

Match each Working Stress beam quantity with its correct expression:
1. Neutral-axis equation for a cracked singly reinforced rectangle
2. Balanced neutral-axis factor
3. Lever-arm factor
4. Final steel-controlled moment expression

P. j = 1 - k/3
Q. M = Astσst(d - x/3)
R. bx²/2 = mAst(d - x)
S. k = 1/[1 + σst/(mσcbc)]

Which matching is correct?

A 1-R, 2-S, 3-P, 4-Q B 1-S, 2-R, 3-Q, 4-P C 1-Q, 2-P, 3-S, 4-R D 1-P, 2-Q, 3-R, 4-S

Answer Key || సమాధానాల పట్టిక

Related Quizzes || సంబంధిత క్విజ్‌లు

Civil HMWSSB, Unit 3 - Cement Concrete and Steel Structures Quiz

TGPSC HMWSSB Quiz

Answer Key సమాధానాల పట్టిక

Related Quizzes సంబంధిత క్విజ్‌లు