Engineering Questions with Answers - Multiple Choice Questions

# Strength of Materials MCQs Maximum Shear Force

1 - Question

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

Explanation: 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 - Question

At hinge, the moments will be _________
a) Maximum
b) Minimum
c) Uniform
d) Zero

Explanation: 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 - Question

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

Explanation: 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 - Question

The rate of change of shear force is equal to _____
b) Change in BMD
d) Maximum bending

Explanation: Consider a simply supported beam subjected to udl for the entire span considered a free body diagram of small portion of elemental length dx. 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 - Question

The shear force in a beam subjected to pure positive bending is _____
a) Positive
b) Negative
c) Zero
d) Cannot determine

Explanation: 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 - Question

In SFD, vertical lines are for ______
b) UDL
c) UVL
d) LDP

Explanation: 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 - Question

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

Explanation: 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 - Question

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

Explanation: 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 - Question

At the Point of contraflexure, what is the value of bending moment?
a) one
b) zero
c) three
d) infinity

Explanation: 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 - Question

When SF is zero, the bending moment is _____
a) Zero
b) Maximum
c) Very difficult to say
d) Minimum

Explanation: 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.

11 - Question

Strength of Materials MCQs Maximum Bending Moment

A cantilever beam subjected to point load at its free end, the maximum bending moment develops at the ________ of the beam.
a) Free end
b) Fixed end
c) Centre
d) Point of inflection

Explanation: As the moment is the product of perpendicular distance and force. In cantilever beam, at its free end the moment will be zero as there is no distance, but at the fixed end the moment is maximum that is W×l.

12 - Question

Bending moment in a beam is maximum when the _________
a) Shear force is minimum
b) Shear force is maximum
c) Shear force is zero
d) Shear force is constant

Explanation: The maximum bending moment occurs in a beam, when the shear force at that section is zero or changes the sign because at point of contra flexure the bending moment is zero.

13 - Question

Positive bending moment is known as _______
a) Hogging
b) Sagging
c) Ragging
d) Inflection

Explanation: The positive bending moment in a section is considered because it causes convexity downwards. Such bending moment is called a sagging bending moment or positive bending moment.

14 - Question

A simply supported beam of span “x” meters carries a udl of “w” per unit length over the entire span, the maximum bending moment occurs at _____
a) At point of contra flexure
b) Centre
c) End supports
d) Anywhere on the beam

Explanation: As we know that BM occurs at center. Because at supports the moment is obviously zero.
At the centre, maximum bending moment is wl2/8. 15 - Question

The maximum BM is ______
a) 40 kNm
b) 50 kNm
c) 90 kNm
d) 75 kNm

Explanation: Above diagram depicts cantilever beam subjected to point load at the free end. The maximum bending moment at A is W × I
= 30 × 3
= 90 kNm.

16 - Question

Bending moment can be denoted by ____
a) K
b) M
c) N
d) F

Explanation: Bending moment is the product of force and perpendicular distance. Units are kNm
It is denoted by “M”. Whereas SF is denoted by “F”.

17 - Question

Number of points of contra flexure for a double over hanging beam.
a) 3
b) 2
c) 4
d) Infinite

Explanation: Point of contraflexure in a beam is a point at which bending moment changes its sign from positive to negative and vice versa. In the case of overhanging beam, there will be two points of contraflexure.

18 - Question

Maximum bending moment in a cantilever beam subjected to udl (w)over the entire span (l).
a) wl
b) wl3
c) wl2
d) w

Explanation: In a cantilever beam the maximum bending moment occurs at the fixed end. Moment at the free end is 0 and maximum at the fixed end. Maximum shear force is w×l.

19 - Question

Determine the maximum bending moment for the below figure.<br/> a) wl/2<br/>
b) wl/3<br/>
c) wl/4<br/>
d) wl

Explanation: First of all, let’s assume the length between end supports be ”l” the maximum bending moment in a simply supported beam with point load at its centre is wl/4. We know that in simply supported beam the maximum bending moment occurs at the centre only.

20 - Question

What is the variation in the BM, if the simply supported beam carries a point load at the centre.
a) Triangular
b) Rectangular
c) Trapezoidal

Explanation: For simply supported beam with point load at the centre, the maximum bending moment will be at the centre i.e. wl/4. The variation in bending moment is triangular. 21 - Question

### Strength of Materials MCQs Shear Force and Bending Moment diagram

What is the bending moment at end supports of a simply supported beam?
a) Maximum
b) Minimum
c) Zero
d) Uniform

Explanation: At the end supports, the moment (couple) developed is zero, because there is no distance to take the perpendicular acting load. As the distance is zero, the moment is obviously zero.

22 - Question

What is the maximum shear force, when a cantilever beam is loaded with udl throughout?
a) w×l
b) w
c) w/l
d) w+l

Explanation: In cantilever beams, the maximum shear force occurs at the fixed end. In the free end, there is zero shear force. As we need to convert the udl in to load, we multiply the length of the cantilever beam with udl acting upon. For maximum shear force to obtain we ought to multiply load and distance and it surely occurs at the fixed end (w×l).

23 - Question

Sagging, the bending moment occurs at the _____ of the beam.
a) At supports
b) Mid span
c) Point of contraflexure
d) Point of emergence

Explanation: The positive bending moment is considered when it causes convexity downward or concavity at top. This is sagging. In simply supported beams, it occurs at mid span because the bending moment at the supports obviously will be zero hence the positive bending moment occurs in the mid span.

24 - Question

What will be the variation in BMD for the diagram? [Assume l = 2m].<br/> a) Rectangular<br/>
b) Trapezoidal<br/>
c) Triangular<br/>
d) Square

Explanation: At support B, the BM is zero. The beam undergoes maximum BM at fixed end.
By joining the base line, free end and maximum BM point. We obtain a right angled triangle. 25 - Question

What is the maximum bending moment for simply supported beam carrying a point load “W” kN at its centre?
a) W kNm
b) W/m kNm
c) W×l kNm
d) W×l/4 kNm

Explanation: We know that in simply supported beams the maximum BM occurs at the central span.
Moment at A = Moment at B = 0
Moment at C = W/2 × l/2 = Wl/ 4 kNm (Sagging).

26 - Question

How do point loads and udl be represented in SFD?
a) Simple lines and curved lines
b) Curved lines and inclined lines
c) Simple lines and inclined lines
d) Cant represent any more

Explanation: According to BIS, the standard symbols used for sketching SFD are 27 - Question

________ curve is formed due to bending of over hanging beams.
a) Elastic
b) Plastic
c) Flexural
d) Axial

Explanation: The line to which the longitudinal axis of a beam bends or deflects or deviates under given load is known as elastic curve on deflection curve. Elastic curve can also be known as elastic line or elastic axis.

28 - Question

The relation between slope and maximum bending moment is _________
a) Directly proportion
b) Inversely proportion
c) Relative proportion
d) Mutual incidence

Explanation: The relationship between slope and maximum bending moment is inversely proportional because, For example in simply supported beams slope is maximum at supports and zero at midspan of a symmetrically loaded beam where as bending moment is zero at supports and maximum at mid span. Hence we conclude that slope and maximum bending moment are inversely proportional to each other in a case of the simply supported beam.

29 - Question

What is the SF at support B?<br/> a) -54 kNm<br/>
b) -92 kNm<br/>
c) -105 kNm<br/>
d) – 65 kNm

Explanation: Total load = 2×2 = 4kN
Shear force at A = 4 kN ( same between A and C )
Shear force at C = 4 kN
Shear force at B = 0 kN
Maximum SF at A = 4 kN.

30 - Question

Where do the maximum BM occurs for the below diagram.<br/> a) -54 kNm<br/>
b) -92 kNm<br/>
c) -105 kNm<br/>
d) – 65 kNm