250+ TOP MCQs on Portal Frames Numericals and Answers

Posted on April 16, 2024April 16, 2024 by engineerComments Off

Structural Analysis Multiple Choice Questions on “Portal Frames Numericals”.

1. Vertical reaction at support B for the given frame is ______

a) 10kN (Upward)
b) 10kN (Downward)
c) 26kN (Upward)
d) 26kN (Downward)
Answer: c
Clarification:

∑Mb=0
Vb*3-36*1.5-24*1=0
Vb=26kN (Upward)

2. Vertical reaction at support A for the given frame is ______

a) 10kN (Upward)
b) 10kN (Downward)
c) 26kN (Upward)
d) 26kN (Downward)
Answer: a
Clarification:

∑V=0
Va+Vb=36kN
Vb=36-26=10kN (Downward)

3. Moment at support A for the given frame is ______

a) 30kNm (Clockwise)
b) 30kNm (Anticlockwise)
c) 24kNm (Clockwise)
d) 24kNm (Anticlockwise)
Answer: d
Clarification:
Ma=26*3-36*1.5-24*5+30*4
Ma =24kNm (Clockwise)

4. Horizontal reaction at support A for the given frame is ______

a) 3kN (Leftward)
b) 3kN (Rightward)
c) 6kN (Leftward)
d) 6kN (Rightward)
Answer: c
Clarification:

∑H= 0
Ha+24=30
Ha=6 kN (Rightward)

5. Bending Moment Diagram for member AB in the given set of frame is given by ________

a)
b)
c)
d)
View Answer

Answer: c
Clarification: Support A is a fixed having clockwise moment of 24 kNm, but as we proceed along the AB, horizontal force in rightward direction gives anticlockwise moment. Hence, moment at joint B is 24 – 6*4 = 0kNm.

6. Bending Moment Diagram for member AB in the given set of frame is given by _________

a)
b)
c)
d)
Answer: b
Clarification: Support B is a roller support and does not have any horizontal reaction, thus bending moment would continue to be zero until and unless any external horizontal forces acts upon it. Thus bending moment will be maximum at joint C, Mc = 60kNm.

7. What is the support reaction of C for the given frame?

a) 10.5kN (Upward)
b) 10.5kN (Downward)
c) 37.5kN (Upward)
d) 37.5kN (Downward)
Answer: c
Clarification:

∑Mb=0
Vc*4=48*2+36*1.5
Vc=37.5 KN

8. What is vertical support reaction at support A for the given frame?

a) 10.5kN (Upward)
b) 10.5kN (Downward)
c) 37.5kN (Upward)
d) 37.5kN (Downward)
Answer: a
Clarification:

∑V=0
Va+37.5=48
Va=10.5 KN

9. Calculate moment at support at for the given frame.

a) 108kNm (Clockwise)
b) 108kNm (Anticlockwise)
c) 276kNm (Clockwise)
d) 276kNm (Anticlockwise)
View Answer

Answer: c
Clarification:
Moment at A=Ma=56*6-20*3=276 KNm

10. Axial force diagram for the member AB for the given frame is given by ________

a)
b)
c)
d)
Answer: b
Clarification: Since the vertical reaction at the support A is 10.5kN, which is compressive in nature. Therefore, Axial Force Diagram is given by the following figure.

11. Which one of the following is correct shear force diagram for member AB for the given frame?

a)
b)
c)
d)
Answer: a
Clarification: Horizontal support reaction at support A is 56kN and at 3metre above the support horizontal force of 20kN is acting leftward thus reducing shear force diagram value to 36kN.

12. Which one of the following is correct bending moment diagram for member AB for the given frame?

a)
b)
c)
d)
Answer: a
Clarification: Since there’s no external uniformly distributed force is acting on the member, option c and d can be directly eliminated. Bending at support A is 276kNm given by
Moment at A=Ma=56*6-20*3=276 KNm