250+ TOP MCQs on Maximum Shear Force and Answers

This set of Strength of Materials Multiple Choice Questions on “Maximum Shear Force”.

1. Which of these is the correct way of sign convention for shear force?
a) R U P
b) L U P
c) R U N
d) L D P
Answer: c
Clarification: According to the theoretical approach, there are many sign conventions to follow but the standard one is “right upwards negative” the sign convention is thoroughly followed unanimously.

2. At hinge, the moments will be _________
a) Maximum
b) Minimum
c) Uniform
d) Zero
Answer: d
Clarification: At the support of a member, there is no distance prevailing to take the upcoming load. As we know the moment is a product of force and perpendicular distance, but at hinge (end support) the distance is zero. Hence the moment developed is zero.

3. What is variation in SFD, if the type of loading in the simply supported beam is U.D.L is ____
a) Rectangle
b) Linear
c) Trapezoidal
d) Parabolic
Answer: b
Clarification: The shear force is defined as the algebraic sum of all the forces taken from any one of the section. If you figure out the SFD for a simply supported beam carrying U.D.L throughout its entire length, in the SFD we can observe that shear force is same at supports. In the centre, the shear force is zero. Hence the diagram varies linearly.

4. The rate of change of shear force is equal to _____
a) Direction of load
b) Change in BMD
c) Intensity of loading
d) Maximum bending
Answer: c
Clarification: Consider a simply supported beam subjected to udl for the entire span considered a free body diagram of small portion of elemental length dx.
strength-materials-questions-answers-maximum-shear-force-q4
Let the shear force at left of the section is = F
Let the increase in shear force in length of the dx = dF
Let the Indian city of load on this part of the beam = w
Total downward load in this elemental length = wdx
€V = 0
dF = -wdx
dF/dx = -w
This rate of change of shear force at any section is equal to the intensity of loading at that section.

5. The shear force in a beam subjected to pure positive bending is _____
a) Positive
b) Negative
c) Zero
d) Cannot determine
Answer: c
Clarification: In the determination of shear force and bending moment diagrams it is clear that shear force changes its sign when the bending moment in a beam is maximum and the shear force in a beam subjected to pure positive bending will be zero as the neutralizing effect comes under.

6. In SFD, vertical lines are for ______
a) Point loads
b) UDL
c) UVL
d) LDP
Answer: a
Clarification: Shear Force diagram started from left side of the m as per the load. For point loads draw vertical lines and under UDL draw slope lines.

7. A cantilever beam loaded with udl throughout, the maximum shear force occurs at____
a) Free end
b) Fixed end
c) At centre
d) At point of contraflexure
Answer: b
Clarification: In a case of a cantilever beam subjected to udl, at the free end there will be zero shear force because, we need to convert udl to load by multiplying with distance. Hence at the fixed end the shear force is w×l i.e (maximum).

8. A simply supported beam of span 1 m carries a point load “w” in centre determine the shear force in the half left of the beam.
a) W/3
b) W/4
c) W/2
d) W
Answer: c
Clarification: Let the two ends of the beam be A and B, the given load on a beam is symmetrical hence RA = RB= W/2. SFD at any section in the left of the beam is equal to the W/2. SFDat any section in the right half of the beam is equal to -W/2.

9. At the Point of contraflexure, what is the value of bending moment?
a) one
b) zero
c) three
d) infinity
Answer: b
Clarification: Point of contraflexure in a beam is a point at which bending moment changes its sign from positive to negative and vice versa. At the point of contraflexure, the value of bending moment is zero.

10. When SF is zero, the bending moment is _____
a) Zero
b) Maximum
c) Very difficult to say
d) Minimum
Answer: b
Clarification: When is shear force changes its sign, the bending moment in a beam will be either maximum positive or maximum negative. This is because of the sign convention adopted.