250+ TOP MCQs on Arches and Answers

Structural Analysis Multiple Choice Questions on “Arches”.

1. An arch is a beam except for ____
a) It does not resist inclined load
b) It does not resist transverse forces
c) It does not allow rotation at any point
d) It does not allow horizontal movement
Answer: d
Clarification: An arch is a curved member in which horizontal displacements are prevented at the supports/springings/abutments.

2. An arch is more economical than a beam for a shorter span length.
a) True
b) False
Answer: a
Clarification: Bending Moment for an arch is given by the bending moment produced in simply supported for same loading minus bending moment produced due to horizontal thrust. Since the bending moment produced is lower for the same loading, it is more economical than the beam.

3. Two hinged arches is a determinate structure.
a) True
b) False
Answer: b
Clarification: Two hinged arches is an indeterminate structure. We can calculate vertical reactions by using ∑M = 0 and ∑V = 0 but the horizontal reaction cannot be computed by any of equilibrium equations. Thus, two hinged arches is an indeterminate structure.

4. Calculate the horizontal thrust for the two hinged parabolic arch loaded uniformly throughout with distributed load.

a) (frac{WL^2}{32H} )
b) (frac{WL^2}{16H} )
c) (frac{WL^2}{8H} )
d) (frac{WL^2}{2H} )
Answer: c
Clarification: ∑H = 0
H = (frac{∫M.y dy}{∫y^2 dy})
Where, y=(frac{4 H x ( L-x )}{L^2})
Hence, H = (frac{WL^2}{8H} )

5. Calculate the horizontal thrust for the two hinged parabolic arch loaded uniformly for the left half span of the arch with distributed load.

a) (frac{WL^2}{32H} )
b) (frac{WL^2}{16H} )
c) (frac{WL^2}{8H} )
d) (frac{WL^2}{2H} )
Answer: b
Clarification: ∑H = 0
H = (frac{∫M.y dy}{∫y^2 dy})
Where, y=(frac{4 H x ( L-x )}{L^2})
Hence, H = (frac{WL^2}{16H} )

6. Calculate the horizontal thrust for the two hinged semicircular arch loaded uniformly throughout with distributed load.

a) (frac{W}{pi})
b) (frac{W}{pi}) sin2
c) (frac{4RW}{3pi})
d) (frac{W}{2pi})
Answer: c
Clarification: ∑H = 0
H = (frac{∫M.y dy}{∫y^2 dy})
Y = (sqrt{R^2- x^2} – sqrt{R^2-(frac{L^2}{2})} )
Hence, H = (frac{4RW}{3pi}.)

7. Calculate the horizontal thrust for the two hinged semicircular arch loaded with point load at its crown.

a) (frac{W}{pi})
b) (frac{W}{pi}) 2
c) (frac{4RW}{3pi})
d) (frac{W}{2pi})
Answer: a
Clarification: ∑H = 0
H = (frac{∫M.y dy}{∫y^2 dy})
Y = (sqrt{R^2- x^2} – sqrt{R^2-(frac{L^2}{2})} )
Hence, H = (frac{W}{pi})

8. Calculate the horizontal thrust for the two hinged parabolic arch loaded with point load at its crown.

a) (frac{W}{pi})
b) (frac{W}{pi})sin2
c) (frac{4RW}{3pi})
d) (frac{25WL}{128H})
Answer: d
Clarification: ∑H = 0
H = (frac{∫M.y dy}{∫y^2 dy})
Where, y=(frac{4 H x (L-x)}{L^2})
Hence, H = (frac{25WL}{128H}.)

9. Calculate the horizontal thrust for the two hinged semicircular arch loaded with point load at inclination of α with horizontal axis on the left span.

a) (frac{W}{pi})
b) (frac{W}{pi})sin2
c) (frac{4RW}{3pi})
d) (frac{25WL}{128H})
Answer: b
Clarification: ∑H = 0
H = (frac{∫M.y dy}{∫y^2 dy})
Y = (sqrt{R^2- x^2} – sqrt{R^2-(frac{L}{2^2})} )
Hence, H = (frac{W}{pi})sin2∞.

10. Identify the incorrect statement according to the hinged arches.
a) Three hinged arch is a statically determinate structure
b) To analyze three hinged arch, equlibrium equations are sufficient
c) For three hinged parabolic arch subjected to u.d.l over the entire span, the bending moment is constant throughout the span
d) For two hinged parabolic arch subjected to u.d.l over the entire span, the bending moment is zero throughout the span
Answer: c
Clarification: For three hinged parabolic arch subjected to u.d.l over the entire span, the bending moment and radial shear at any section is zero throughout the span.

250+ TOP MCQs on Conjugate-Beam Method – 2 and Answers

Structural Analysis MCQs on “Conjugate-Beam Method – 2”.

B is a hinge support and C is roller support. A and D are free ends. A load of 60 KN acts in downward direction at point D. Sign conventions are as usual.
AB = CD = 1m and BC = 3m
All force options are in kN.
All moment options are in KNM.
All deformation options are in M.
E and I are given.

structural-analysis-questions-answers-mcqs-q1

1. What will be the reaction force at support C?
a) 20
b) 40
c) 80
d) 120
Answer: c
Clarification: Balance moment about point B.

2. What will be the shape of SFD in this case?
a) Linear
b) Parabolic
c) Linear with discontinuity
d) Arbitrary curve
Answer: c
Clarification: Since loads are not uniform, SFD will be linear and support at point C and B will lead to discontinuity.

3. What is the shape of BMD for this diagram?
a) Rectangular
b) Triangular
c) Parabolic
d) Arbitrary curve
Answer: b
Clarification: It will be 0 till point B, and then will increase till C and then again decrease till D (every time linearly), thus making it triangular.

4. What will be the peak value of SFD?
a) 20
b) 40
c) 60
d) 80
Answer: c
Clarification: It will decrease to 20 at point B and then increase by 80 at point C and then will remain constant. So, peak value will be 80-20 i.e. 60KN.

5. Where would peak value of BMD lie?
a) A
b) B
c) C
d) D
Answer: c
Clarification: It will be 0 till point B, and then will increase till C and then again decrease till D (every time linearly), thus making it triangular.

6. Which type of joint would replace point A in its conjugate beam?
a) roller
b) pin
c) hinge
d) fixed
Answer: d
Clarification: Since point A is a free end, a fixed joint would replace it in the conjugate beam.

7. How many fixed joint will be there in conjugate beam?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: Since there are 2 fixed ends in initial beam, there will be two fixed joints.

8. There won’t be any hinge in the conjugate beam.
State whether the above statement is true or false.
a) true
b) false
Answer: b
Clarification: Initial beam comprises of one internal pin and one internal roller, so conjugate beam would contain two hinges.

9. What will be the shear developed at hinge B in conjugate beam?
a) 30/EI
b) 40/EI
c) 60/EI
d) 80/EI
Answer: a
Clarification: Balance moment about point C in the beam BC.

10. What will be the shear developed at hinge C in conjugate beam?
a) 30/EI
b) 40/EI
c) 60/EI
d) 80/EI
Answer: c
Clarification: Balance moment about point B in the beam BC.

11. What will be the modulus of slope at point A?
a) 90/EI
b) 40/EI
c) 30/EI
d) 20/EI
Answer: c
Clarification: Just balance shear forces in the conjugate beam AB.

12. What will be the modulus of slope at point D?
a) 90/EI
b) 40/EI
c) 30/EI
d) 20/EI
Answer: a
Clarification: Just balance shear forces in the conjugate beam CD after balancing moment.

13. What will be the modulus of deflection of point A?
a) 20/EI
b) 30/EI
c) 80/EI
d) 90/EI
Answer: b
Clarification: Balance moment about point B in beam AB.

14. What will be the modulus of deflection of point D?
a) 20/EI
b) 30/EI
c) 80/EI
d) 90/EI
Answer: c
Clarification: Balance moment about point C in beam CD.

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