300+ REAL TIME Strength of Materials Objective Questions & Answers 2023

250+ TOP MCQs on Bending Stress and Answers

Strength of Materials Multiple Choice Questions on “Bending Stress”.

1. A beam is said to be of uniform strength, if ____________
a) B.M. is same throughout the beam
b) Shear stress is the same through the beam
c) Deflection is the same throughout the beam
d) Bending stress is the same at every section along its longitudinal axis
Answer: d
Clarification: Beam is said to be uniform strength if at every section along its longitudinal axis, the bending stress is same.

2. Stress in a beam due to simple bending is ____________
a) Directly proportional
b) Inversely proportional
c) Curvilinearly related
d) None of the mentioned
Answer: a
Clarification: The stress is directly proportional to the load and here the load is in terms of bending. So the stress is directly proportional to bending.

3. Which stress comes when there is an eccentric load applied?
a) Shear stress
b) Bending stress
c) Tensile stress
d) Thermal stress
Answer: b
Clarification: When there is an eccentric load it means that the load is at some distance from the axis. This causes compression in one side and tension on the other. This causes bending stress.

4. What is the expression of the bending equation?
a) M/I = σ/y = E/R
b) M/R = σ/y = E/I
c) M/y = σ/R = E/I
d) M/I = σ/R = E/y
Answer: a
Clarification: The bending equation is given by M/I = σ/y = E/R
where
M is the bending moment
I is the moment of inertia
y is the distance from neutral axis
E is the modulus of elasticity
R is the radius.

5. On bending of a beam, which is the layer which is neither elongated nor shortened?
a) Axis of load
b) Neutral axis
c) Center of gravity
d) None of the mentioned
Answer: b
Clarification: When a beam is in bending the layer in the direction of bending will be In compression and the other will be in tension. One side of the neutral axis will be shortened and the other will be elongated.

6. The bending stress is ____________
a) Directly proportional to the distance of layer from the neutral layer
b) Inversely proportional to the distance of layer from the neutral layer
c) Directly proportional to the neutral layer
d) Does not depend on the distance of layer from the neutral layer
Answer: a
Clarification: From the bending equation M/I = σ/y = E/R
Here stress is directly proportional to the distance of layer from the neutral layer.

7. Consider a 250mmx15mmx10mm steel bar which is free to expand is heated from 15C to 40C. what will be developed?
a) Compressive stress
b) Tensile stress
c) Shear stress
d) No stress
Answer: d
Clarification: If we resist to expand then only stress will develop. Here the bar is free to expand so there will be no stress.

8. The safe stress for a hollow steel column which carries an axial load of 2100 kN is 125 MN/m². if the external diameter of the column is 30cm, what will be the internal diameter?
a) 25 cm
b) 26.19cm
c) 30.14 cm
d) 27.9 cm
Answer: b
Clarification: Area of the cross section of column = π/4 (0.30² – d²) m²
Area = load / stress.
So, π/4 ( 0.30² – d²) m² = 21 / 125
d = 26.19cm.

250+ TOP MCQs on Moment of Inertia and Answers

This set of Strength of Materials Multiple Choice Questions on “Moment of Inertia”.

1. The axis about which moment of area is taken is known as ____________
a) Axis of area
b) Axis of moment
c) Axis of reference
d) Axis of rotation
Answer: c
Clarification: The axis of reference is the axis about which moment of area is taken. Most of the times it is either the standard x or y axis or the centeroidal axis.

2. Point, where the total volume of the body is assumed to be concentrated is ____________
a) Center of area
b) Centroid of volume
c) Centroid of mass
d) All of the mentioned
Answer: b
Clarification: The centroid of the volume is the point where total volume is assumed to be concentrated. It is the geometric centre of a body. If the density is uniform throughout the body, then the center of mass and center of gravity correspond to the centroid of volume. The definition of the centroid of volume is written in terms of ratios of integrals over the volume of the body.

3. What is MOI?
a) ml²
b) mal
c) ar²
d) None of the mentioned
Answer: c
Clarification: The formula of the moment of inertia is, MOI = ar² where
M = mass, a = area, l = length, r = distance.

4. What is the formula of radius of gyration?
a) k² = I/A
b) k² = I²/A
c) k² = I²/A²
d) k² = (I/A)^1/2
Answer: a
Clarification: The radius of gyration of a body about an axis is a distance such that its square multiplied by the area gives moment of inertia of the area about the given axis. The formula of radius of gyration is given as k² = I/A.

5. What is the formula of theorem of perpendicular axis?
a) I_zz = I_xx – I_yy
b) I_zz = I_xx + Ah²
c) I_zz – I_xx = I_yy
d) None of the mentioned
Answer: c
Clarification: Theorem of perpendicular axis stares that if I_XX and I_YY be the moment of inertia of a plane section about two mutually perpendicular axis X-X and Y-Y in the plane of the section then the moment of inertia of the section I_ZZ about the axis Z-Z, perpendicular to the plane and passing through the intersection of X-X and Y-Y is given by the formula
I_zz – I_xx = I_yy.

6. What is the formula of theorem of parallel axis?
a) I_AD = I_G + Ah
b) I_AB = Ah² + IG
c) I_AB = I_G – Ah²
d) I_AB = I_G + I_xx
Answer: b
Clarification: The theorem of parallel axis states that if the moment of inertia of a plane area about an axis in the plane of area theough the C.G. of the plane area be represented by IG, then the moment of the inertia of the given plane area about a parallel axis AB in the plane of area at a distance h from the C.G. is given by the formula
I_AB = Ah² + I_G.

7. What is the unit of radius of gyration?
a) m⁴
b) m
c) N
d) m²
Answer: b
Clarification: The radius of gyration = (length⁴/length²)1/2 = length
So its unit will be m.

8. What will be the the radius of gyration of a circular plate of diameter 10cm?
a) 1.5cm
b) 2.0cm
c) 2.5cm
d) 3cm
Answer: c
Clarification: The moment of inertia of a circle, I = πD⁴/64 = 491.07 cm⁴
The area of circle = 78.57 cm,
Radius of gyration = (I/A)^1/2 = 2.5 cm.

250+ TOP MCQs on Shear Stress Distribution in Various Sections and Answers

Basic Strength of Materials Questions and Answers on “Shear Stress Distribution in Various Sections”.

1. A beam has a triangular cross-section, having altitude ”h” and base “b”. If the section is being subjected to a shear force “F”. Calculate the shear stress at the level of neutral axis in the cross section.
a) 4F/5bh
b) 4F/3bh
c) 8F/3bh
d) 3F/4bh

Answer: c
Clarification: For a triangular section subjected to a shear force, the shear stress at neutral axis is
= 4/3 × average shear stress
= 4/3 × F/A/2 ; A = bh
= 8F/3bh.

2. The maximum shear stress in the rectangular section is ______________ times the average shear stress.
a) 3/4
b) 3/7
c) 5/3
d) 3/2

Answer: d
Clarification: The maximum shear stress occurs at the neutral axis. So, y = 0.
Maximum shear stress = 3/2 × F/bd (• Average shear stress = F/bd ).
= 3/2 × average shear stress.

3.The modular ratio for M20 grade concrete is _____________
a) 16
b) 13
c) 11
d) 07

Answer: b
Clarification: According to Indian Standards 456-2000 The modular ratio (m) = 280/3× cbc, For M20; compressive bearing capacity in concrete = 7 N/mm² & tensile strength = 330 N/mm².
Modular ratio (m) = 280/21 = 13.33.

4. In doubly reinforced beam, the maximum shear stress occurs ______________
a) along the centroid
b) along the neutral axis
c) on the planes between neutral axis and tensile reinforcement
d) on the planes between neutral axis and compressive reinforcement

Answer: d
Clarification: In continuous beam the moments developed at the supports are greater than a moment’s developed at the mid span, show the maximum bending moment occurs at the supports.
For continuous beams, the maximum shear stress occurs at the planes intersecting the compressive reinforcement and the neutral axis.

5. A cylindrical section having no joint is known as _______________
a) Proof section
b) Seamless section
c) Target section
d) Mown section

Answer: b
Clarification: A cylindrical section having no joint is known as seamless section. Built up section is not that strong as a seamless section of the same thickness.

6. The efficiency of cylindrical section is the ratio of the strength of joint to the strength of _______________
a) Solid plate
b) Boilerplate
c) Circumferential plate
d) Longitudinal plate

Answer: a
Clarification: The strength of plate or strength of rivet whichever is less is called the strength of joint. The ratio of the strength of joint to the strength of steel plate is called the efficiency of the cylinder.

7. Calculate the modulus of section for a hollow circular column of external diameter 60 mm and 10 mm thickness.
a) 170 m
b) 190 m
c) 250 m
d) 300 m
Answer: a

8. Determine the modulus of a section for an I section, given the distance from neutral axis is 50 mm and moment of inertia is 2.8×10⁶ mm⁴.
a) 59m
b) 51m
c) 58m
d) 63m

Answer: c
Clarification: The modulus of section is the ratio of the moment of inertia to the distance of the neutral axis.
Given y = 50 mm
I = 2.8×10⁶ mm⁴.
& Z = I/y = 2.8×10⁶ / 50
= 57.76 ×10³ mm
= 57.7 ~ 58 m.

9. A circular Beam of 0.25 m diameter is subjected to you shear force of 10 kN. Calculate the value of maximum shear stress. [Take area = 176 m²].
a) 0.75 N/mm²
b) 0.58 N/mm²
c) 0.73 N/mm²
d) 0.65 N/mm²

Answer: a
Clarification: Given diameter = 0.25 m
Area (A) = 176 m²
Shear Force (F) = 10 kN ~ 10000 N.
For circular cross section the maximum shear stress is equal to 4/3 times of average shear stress
Maximum shear force = 4/3 × F/A
= 4/3 × 10000/176
= 0.75 N/mm².

10. The maximum shear stress distribution is _____________ percentage more than average shear stress in circular section.
a) 54 %
b) 60 %
c) 33 %
d) 50 %

Answer: c
Clarification: Maximum shear stress occurs at neutral axis; y =0
Maximum shear stress = 16/3 × average shear stress
But 4F / A is the average shear stress.
So, the maximum shear stress = 4/3 times the average shear stress.
Hence the maximum shear stress is 33% more than the average shear stress in a circular section.

250+ TOP MCQs on Deflection of Simply Supported and Answers

This set of Strength of Materials Multiple Choice Questions on “Deflection of Simply Supported”.

1. __________ of a beam is a measure of its resistance against deflection.
a) Strength
b) Stiffness
c) Slope
d) Maximum bending
Answer: b
Clarification: The ratio of maximum deflection of a beam to its corresponding span is termed as the stiffness of the beam. It is the measure of resistance against the deflection.

2. The maximum induced ___________ stresses should be within the safe permissible stresses to ensure strength of the beam.
a) Tensile
b) Compressive
c) Bending
d) Lateral
Answer: c
Clarification: A beam is said to be strengthy when the maximum induced bending and shear stresses are within the safe permissible stresses of the beam material.

3. Elastic line is also called as ___________
a) Deflection curve
b) Plastic curve
c) Linear curve
d) Hooke’s curve
Answer: a
Clarification: The deflection curve is defined as the line to which the longitudinal axis of a beam deflects or bends under given load. This curve is also known as elastic line or elastic axis.

4. In simply supported beams, the slope is _____________ at supports.
a) Minimum
b) Zero
c) Maximum
d) Uniform
Answer: c
Clarification: The slope at any section in the deflected beam is defined as the angle developed in radians which the tangent at the section makes with the actual axis of the proposed beam. In simply supported beams, the slope is maximum at the supports.

5. In simply supported beam deflection is maximum at ____________
a) Midspan
b) Supports
c) Point of loading
d) Through out
Answer: a
Clarification: In simply supported beams, deflection is maximum at the mid span of a symmetrically loaded beam.

6. Calculate the maximum deflection of a simply supported beam if the maximum slope at A is 0.0075 radians and the distance of centre of gravity of bending moment diagram to support A is 1.33 metres.
a) 9.975 mm
b) 9.5 mm
c) 9.25 mm
d) 9.785 mm
Answer: a
Clarification: The deflection occurs at support A = A/EI = 0.0075 radians
Maximum deflection = Ax/EI = 0.0075 × 1.33
y = 9.975 mm.

7. ____________ is the best example for accelerator (admixture).
a) Sulphonated formaldehyde
b) Calcium chloride
c) Sulphonated naphthalene
d) Polyglycolesters
Answer: b
Clarification: Calcium chloride is more widely used as an accelerator. By adding two percent (2%) of the weight of cacl2 admixture to the Portland cement the Maximum strength is attained within 1-3 days.

8. _____________ is used to reduce the time for hardening of concrete.
a) Accelerators
b) Super plasticizer
c) Retarder
d) Air entraining admixture
Answer: c
Clarification: The admixtures (retarders) are generally used to reduce the time for hardening of concrete. They are used in situations like:
i. In hot weather condition, a tendency towards false set is corrected
ii. When concrete is to be placed in difficult positions.

9. Full form of LEED ________
a) Leadership in Energy and Efficiency Development
b) Leadership in Environmental and Energy Design
c) Leadership in Energy and Environmental Design
d) Leadership in Efflorescence and Energy Demand
Answer: c
Clarification: LEED stands for Leadership in Energy and Environmental Design. The fly ash is environmentally friendly solutions that meet or exceed performance specifications fly ash contributes a lot to LEED.

10. _____ has a lower heat of hydration.
a) Quarry dust
b) Fly ash
c) Ordinary Portland cement
d) Bulk sand
Answer: b
Clarification: The process that liberates heat when water is added to cement is known as heat of hydration. The process of hydration is not instantaneous. The fly ash is possessing lower heat of hydration.

11. The factors that influence rate of hydration is _________
a) The fineness of cement
b) Temperature of cement
c) Quality of water
d) Temperature of water
Answer: a
Clarification: The products of hydration are colloidal and increase the surface area of solid paste during hydration and the water is the main ingredient which reacts chemically. The rate of hydration is mainly influenced by temperature of cement.

12. The steel suits best to reinforcement with concrete.
a) False
b) True
Answer: b
Clarification: The Steel is be used for reinforcing a concrete for following properties:
i. Steel is about 30 times stronger in compression and 300 times stronger intention compared to concrete.
ii. It develops good bond with concrete
iii. It is highly fire resistant.

13. The average crushing strength of precast concrete blocks as per CAI is __________
a) 4.5 N/mm²
b) 5 N/mm²
c) 3.5 N/mm²
d) 4 N/mm²
Answer: c
Clarification: Hollow concrete blocks are used in load bearing walls. In the manufacture of these blocks, the light height aggregates are used. The recommended size is 39 × 19 × 30 cm.
The average crushing strength of blocks Shall be 5N/mm².

14. A simply supported beam of span as shown in the figure is subjected to a concentrated load w at its metre span and also to a uniformly distributed load equality w what is the total diffraction it its midpoint.
a) 18 Wl³ /384 EI
b) 13 Wl³/ 384 EI
c) 5 Wl³/ 384 EI
d) 18 Wl³/ 384 EI
Answer: b
Clarification: The total deflection at midpoint of a simply supported beam is

y = 5Wl³/ 384 EI + Wl³/ 48 EI
y = 13Wl³/ 384 EI.

15. Meander ratio is the ratio of meander belt to __________
a) Meander depth
b) Meander width
c) Meander length
d) Meander cross-section
Answer: c
Clarification: When a river departs from its straight course and follows a sinuous winding path, the river is said to be meandering. Meander ratio is the ratio of meander belt to the meander length.

Strength of Materials Multiple Choice Questions on “Tensile Stress”.

1. During a tensile test on a ductile material ____________
a) Nominal stress at fracture is higher than the ultimate stress
b) True stress at fracture is higher than the ultimate stress
c) True stress a fracture is the same as the ultimate stress
d) None of the mentioned
Answer: b
Clarification: In a ductile material, the true stress at fracture will be higher the ultimate stress.

2. When equal and opposite forces applied to a body, tend to elongate it, the stress so produced, is called ____________
a) Shear stress
b) Compressive stress
c) Tensile stress
d) Transverse stress
Answer: c
Clarification: When subjected to two equal and opposite pulls as a result of which there is an increase in length. This produces tensile stress.

3. Which of the following stresses are associated with the tightening of a nut on a bolt?
P. Tensile stress due to the streching of bolt
Q. Bending stress due to the bending of bolt
R. Torsional shear stress due to frictional resistance between the nut and the bolt
Select the correct answer using the codes given below.
a) P and Q
b) P and R
c) Only p
d) R and Q
Answer: a
Clarification: Bending stress comes when there is some kind of eccentric load. When nut is tightened, the bolt will pull itself and stretching will be there resulting in the tensile stress. Torsional stress will come when the nut is rotating.

4. In a tensile test, near the elastic limit zone ____________
a) Tensile stress increases in linear proportion to the stress
b) Tensile stress increases at a faster rate
c) Tensile stress decreases at a faster rate
d) None of the mentioned
Answer: c
Clarification: The stress first decreases and then decreases before the strain hardening occurs. The decreases in the stress is due to the attraction between carbon molecules.

5. Match the following and give the correct code given in options:

List 1	List 2
A. Tensile test on CI	1. Plain fracture on a transverse plane
B. Tensile test on MS	2. Granular helecoidal fracture
C. Torsion test on CI	3. Cup and cone
	4. Granular fracture in a transverse plane

a) A – 1 B – 2 C – 4
b) A – 1 B – 4 C – 2
c) A – 3 B – 1 C – 2
d) A – 3 B – 4 C – 1
Answer: d
Clarification: Tensile test on CI is done on cup and cone. Torsion test on MS is on plain fracture on a traverse plane.

6. The phenomenon of slow growth of strain under a steady tensile stress is called ____________
a) Yielding
b) Creeping
c) Breaking
d) None of the mentioned
Answer: b
Clarification: Creeping is the phenomenon of slow growing strain under a stress for a period of time.

7. A rod 150cm long and of diameter 2cm is subjected to an axial pull of 20kN. What will be the stress?
a) 60 N/mm²
b) 65 N/mm²
c) 63.6 N/mm²
d) 71.2 N/mm²
Answer: c
Clarification: The stress = load / area
Load = 20,000N
Area = π/4 (20)2 = 100π mm².

8. The stress in a rod is 70 N/mm² and the modulus of elasticity is 2 x 10⁵ N/mm². what will be the strain in the rod?
a) 0.00052
b) 0.00035
c) 0.00030
d) 0.00047
Answer: b
Clarification: As E = σ/e
Here, E = 2 * 10⁵ N/mm²
And, σ = 70 N/mm²
e = 70/2*10⁵ = 0.00035.

9. What will be the minimum diameter of a steel wire, which is used to raise a load of 4000N if the stress in the rod is not to exceed 95 MN/m²?
a) 6mm
b) 6.4mm
c) 7mm
d) 7.3mm
Answer: d
Clarification: As stress = load / area
Area = load/stress
Also, area is π/4 D2 so π/4 D2 = 4000 / 95
And D = 7.32.

10. A tensile test was conducted on mild steel bar. The load at elastic limit was 250kN and the diameter of the steel bar was 3cm. What will be the value of stress?
a) 35368 x 10⁴ N/m²
b) 32463 x 10⁴ N/m²
c) 35625 x 10⁴ N/m²
d) 37562 x 10⁴ N/m²
Answer: a
Clarification: The stress = load / area
Load = 150 x 1000N
Area = π/4 (0.03)² m2.

Category: Strength of Materials Objective Questions

250+ TOP MCQs on Bending Stress and Answers

250+ TOP MCQs on Moment of Inertia and Answers

250+ TOP MCQs on Shear Stress Distribution in Various Sections and Answers

250+ TOP MCQs on Deflection of Simply Supported and Answers

250+ TOP MCQs on Tensile Stress and Answers

250+ TOP MCQs on Moment of Inertia of Section and Answers