# Strength of Materials MCQ Questions & Answers

Strength of Materials MCQs : This section focuses on the "Strength of Materials". These Multiple Choice Questions (MCQs) should be practiced to improve the Strength of Materials skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

A beam supported at its both ends is not a simply supported beam.

A. TRUE
B. FALSE

Question 2

A body is subjected to a tensile stress of 1200 MPa on one plane and another tensile stress of 600 MPa on a plane at right angles to the former. It is also subjected to a shear stress of 400 MPa on the same planes. The maximum normal stress will be

A. 400 MPa
B. 500 MPa
C. 900 MPa
D. 1400 MPa

Question 3

A concentrated load is one which

A. acts at a point on a beam
B. spreads non-uniformly over the whole length of a beam
C. spreads uniformly over the whole length of a beam
D. varies uniformly over the whole length of a beam

Question 4

A load which is spread over a beam in such a manner that it varies uniformly over the whole length of abeam is called uniformly __________ load.

A. distributed
B. varying

Question 5

A masonry dam may fail due to

A. tension in the masonry of the dam and its base
B. overturning of the dam
C. crushing of masonry at the base of the dam
D. any one of the above

Question 6

A steel bar of 5 mm is heated from 15° C to 40° C and it is free to expand. The bar Will induce

A. no stress
B. shear stress
C. tensile stress
D. compressive stress

Question 7

A vertical column has two moments of inertia (i.e. Ixx and Iyy ). The column will tend to buckle in the direction of the

B. perpendicular to the axis of load
C. maximum moment of inertia
D. minimum moment of inertia

Question 8

Euler's formula holds good only for

A. short columns
B. long columns
C. both short and long columns
D. weak columns

Question 9

If the depth is kept constant for a beam of uniform strength, then its width will vary in proportional to (where M = Bending moment)

A. M
B. M
C. M2
D. M3

Question 10

If the slenderness ratio for a column is 100, then it is said to be a __________ column.

A. long
B. medium
C. short

Question 11

If the tearing efficiency of a riveted joint is 50%, then ratio of rivet hole diameter to the pitch of rivets is

A. 0.2
B. 0.3
C. 0.5
D. 0.6

Question 12

In a simple bending of beams, the stress in the beam varies

A. linearly
B. parabolically
C. hyperbolically
D. elliptically

Question 13

In compression test, the fracture in cast iron specimen would occur along

B. an oblique plane
C. at right angles to the axis of specimen
D. would not occur

Question 14

In order to know whether a column is long or short, we must know its slenderness ratio.

A. TRUE
B. FALSE

Question 15

In order to prevent crushing of masonry at the base of the dam, the maximum stress should be __________ the permissible stress of the soil.

A. equal to
B. less than
C. more than

Question 16

Resilience is the

A. energy stored in a body when strained within elastic limits
B. energy stored in a body when strained upto the breaking of the specimen
C. maximum strain energy which can be stored in a body
D. none of the above

Question 17

Strain energy is the

A. energy stored in a body when strained within elastic limits
B. energy stored in a body when strained upto the breaking of a specimen
C. maximum strain energy which can be stored in a body
D. proof resilience per unit volume of a material

Question 18

Strain rosettes are used to

A. measure shear strain
B. measure linear strain
C. measure volumetric strain
D. relieve strain

Question 19

The bending moment at a point on a beam is the algebraic __________ of all the moments on either side of the point.

A. sum
B. difference

Question 20

The bending stress in a beam is __________ section modulus.

A. directly proportional to
B. inversely proportional to

Question 21

The deformation per unit length is called

A. tensile stress
B. compressive stress
C. shear stress
D. strain

Question 22

The energy stored in a body when strained within elastic limit is known as

A. resilience
B. proof resilience
C. strain energy
D. impact energy

Question 23

The limit of eccentricity is based upon no tension condition.

A. TRUE
B. FALSE

Question 24

The maximum diameter of the hole that can be punched from a plate of maximum shear stress 1/4th of its maximum crushing stress of punch, is equal to (where t = Thickness of the plate)

A. t
B. 2t
C. 4t
D. 8t

Question 25

The maximum stress produced in a bar of tapering section is at

A. smaller end
B. larger end
C. middle
D. anywhere

Question 26

The neutral axis of the cross-section a beam is that axis at which the bending stress is

A. zero
B. minimum
C. maximum
D. infinity

Question 27

The object of caulking in a riveted joint is to make the joint

A. free from corrosion
B. stronger in tension
C. free from stresses
D. leak-proof

Question 28

The point of contraflexure is a point where

A. shear force changes sign
B. bending moment changes sign
C. shear force is maximum
D. bending moment is maximum

Question 29

The rectangular beam 'A' has length l, width b and depth d. Another beam 'B' has the same length and depth but width is double that of 'A'. The elastic strength of beam 'B' will be __________ as compared to beam A.

A. same
B. double
C. four times
D. six times

Question 30

The simply supported beam 'A' of length l carries a central point load W. Another beam 'B' is loaded with a uniformly distributed load such that the total load on the beam is W. The ratio of maximum deflections between beams A and B is

A. 05-Aug
B. 08-May
C. 05-Apr
D. 04-May

Question 31

The strain energy stored in a solid circular shaft subjected to shear stress (τ) is (where C = Modulus of rigidity for the shaft material)

A. x Volume of shaft
B. x Volume of shaft
C. x Volume of shaft
D. x Volume of shaft

Question 32

The stress at which the extension of the material takes place more quickly as compared to the increase in load, is called

A. elastic limit
B. yield point
C. ultimate point
D. breaking point

Question 33

The stress induced in a body, when suddenly loaded, is __________ the stress induced when the same load is applied gradually.

A. equal to
B. one-half
C. twice
D. four times

Question 34

The torque transmitted by a solid shaft of diameter (D) is (where τ = Maximum allowable shear stress)

A. x τ x D3
B. x τ x D3
C. x τ x D3
D. x τ x D3

Question 35

Two closely coiled helical springs 'A' and 'B' are equal in all respects but the number of turns of spring 'A' is half that of spring 'B' The ratio of deflections in spring 'A' to spring 'B' is

A. 01-Aug
B. 01-Apr
C. 01-Feb
D. 2

Question 36

Two shafts 'A' and 'B' transmit the same power. The speed of shaft 'A' is 250 r.p.m. and that of shaft 'B' is 300 r.p.m. The shaft 'B' has the greater diameter.

A. TRUE
B. FALSE

Question 37

When a bar is cooled to - 5°C, it will develop

A. no stress
B. shear stress
C. tensile stress
D. compressive stress

Question 38

When a body is subjected to two equal and opposite pushes, as a result of which the body tends to reduce its length, the stress and strain induced is compressive.

A. TRUE
B. FALSE

Question 39

When a rectangular beam is loaded transversely, the maximum compressive stress is developed on the

A. top layer
B. bottom layer
C. neutral axis
D. every cross-section

Question 40

When shear force at a point is zero, then bending moment is __________ at that point.

A. zero
B. minimum
C. maximum
D. infinity

Question 41

When two main plates are kept in alignment butting each other and riveted with cover plate on both sides of the main plates with two rows of rivets in each main plate, the joint is known as __________ double cover butt joint.

A. single riveted
B. double riveted

Question 42

Whenever a material is loaded within elastic limit, stress is __________ strain.

A. equal to
B. directly proportional to
C. inversely proportional to

Question 43

Which of the following statement is correct?

A. The energy stored in a body, when strained within elastic limit is known as strain energy.
B. The maximum strain energy which can be stored in a body is termed as proof resilience.
C. The proof resilience per unit volume of a material is known as modulus of resilience.
D. all of the above

Question 44

A beam is said to be of uniform strength, if

A. B.M. is same throughout the beam
B. deflection is same throughout the beam
C. bending stress is same throughout the beam
D. shear stress is same throughout the beam

Question 45

A beam of length L is pinned at both ends and is subjected to a concentrated bending couple of moment M at its centre. The maximum bending moment in the beam is

A. M
B. M/2
C. M/3
D. ML/2

Question 46

A rectangular beam 20 cm wide is subjected to a maximum shearing force of 10, 000 kg, the corresponding maximum shearing stress being 30 kg/cm2. The depth of the beam is

A. 15 cm
B. 20 cm
C. 25 cm
D. 30 cm.

Question 47

A reinforced concrete beam is assumed to be made of

A. homogeneous material
B. heterogeneous material
C. isotropic material
D. none of these.

Question 48

A shaft turning 150 r.p.m. is subjected to a torque of 150 kgm. Horse power transmitted by the shaft is

A. π
B. 10 π
C. π2
D. 1/π

Question 49

A simply supported beam carrying a uniformly distributed load over its whole span, is propped at the centre of the span so that the beam is held to the level of the end supports. The reaction of the prop will be

Question 50

A three-hinged arch is said to be :

A. statically determinate structure
B. statically indeterminate structure
C. a bent beam
D. none of these.

Question 51

For a given material Young's modulus is 200 GN/m2 and modulus of rigidity is 80 GN/m2. The value of Poisson's ratio is

A. 0.15
B. 0.2
C. 0.25
D. 0.3

Question 52

For a simply supported beam of length L, the bending moment M is described as M = a (x - x3/L2), 0 ≤ x < L; where a is a constant. The shear force will be zero at

A. the supports
B. x = L/2
C. x = L/3
D. x = L/3

Question 53

For a simply supported beam with a central load, the bending moment is

A. least at the centre
B. least at the supports
C. maximum at the supports
D. maximum at the centre.

Question 54

If a rectangular beam measuring 10 x 18 x 400 cm carries a unformly distributed load such that the bending stress developed is 100 kg/cm2. The intensity of the load per metre length, is

A. 240 kg
B. 250 kg
C. 260 kg
D. 270 kg

Question 55

If the rivets in adjacent rows are staggered and outermost row has only one rivet, the arrangement of the rivets, is called

A. chain riveting
B. zig-zag riveting
C. diamond riveting
D. none of these.

Question 56

If the shear force along a section of a beam is zero, the bending moment at the section is

A. zero
B. maximum
C. minimum
D. average of maximum-minimum

Question 57

If the width of a simply supported beam carrying an isolated load at its centre is doubled, the deflection of the beam at the centre is changed by

A. 01-Feb
B. 01-Aug
C. 2
D. 8

Question 58

If two forces acting at a joint are not along the straight line, then for the equilibrium of the joint

A. one of the forces must be zero
B. each force must be zero
C. forces must be equal and of the same sign
D. forces must be equal in magnitude but opposite in sign.

Question 59

In a beam, the neutral plane

A. may be its centre
B. passes through the C.G. of the area of cross-section
C. does not change during deformation
D. none of these.

Question 60

In a loaded beam, the point of con-traflexture occurs at a section where

A. bending moment is minimum
B. bending moment is zero or changes sign
C. bending moment is maximum
D. shearing force is maximum

Question 61

In a tension test, the yield stress is 300 kg/cm2, in the octa hedral shear stress at the point is:

A. 100 2 kg/cm2
B. 150 2 kg/cm2
C. 200 2 kg/cm
D. 250 2 kg/cm2.

Question 62

Influence lines are drawn for structures

A. of any type
B. statically determinate
C. pin-jointed truss
D. none of these.

Question 63

The deflection of any rectangular beam simply supported, is

A. directly proportional to its weight
B. inversely proportional to its width
C. inversely proportional to the cube of its depth
D. directly proportional to the cube of its length

Question 64

The maximum twisting moment a shaft can resist, is the product of the permissible shear stress and

A. moment of inertia
B. polar moment of inertia
C. polar modulus
D. modulus of rigidly.

Question 65

The minimum number of rivets for the connection of a gusset plate, is

A. 1
B. 2
C. 3
D. 4

Question 66

The radius of gyration of a rectangular section is not proportional to

A. square root of the moment of inertia
B. square root of the inverse of the area
C. square root of the moment of inertia divided by area of the section
D. none of these.

Question 67

The range within which a load can be applied on a rectangular column, to avoid any tensile stress, is

A. one-half of the base
B. one-third of the base
C. one-fourth of the base
D. one-fifth of the base

Question 68

The ratio of strengths of solid to hollow shafts, both having outside diameter D and hollow having inside diameter D/2, in torsion, is

A. 01-Apr
B. 01-Feb
C. Jan-16
D. 15/16

Question 69

The ratio of the moment of inertia of a circular plate and that of a square plate for equal depth, is

A. less than one
B. equal to one
C. more than one
D. equal to 3π/16

Question 70

The region of the cross-section of a column in which compressive load may be applied without producing any tensile stress, is known as the core of the cross-section. In circular columns the radius of the core, is

Question 71

The shape of the bending moment diagram over the length of a beam, carrying a uniformly distributed load is always

A. linear
B. parabolic
C. cubical
D. circular.

Question 72

The shape of the bending moment diagram over the length of a beam, having no external load, is always

A. linear
B. parabolic
C. cubical
D. circular.

Question 73

The shear stress at any section of a shaft is maximum

A. at the centre of the section
B. at a distance r/2 from the centre
C. at the top of the surface
D. at a distance 3/4 r from the centre

Question 74

The slenderness ratio of a vertical column of a square cross-section of 2.5 cm sides and 300 cm length, is

A. 200
B. 240
C. 360
D. 416

Question 75

The weakest section of a diamond riveting, is the section which passes through

A. first row
B. second row
C. central raw
D. one rivet hole of end row.

Question 76

When loads are applied proportionately to a frame structure containing its members in one plane, the structure is called

A. grid frame
B. plane frame
C. space frame
D. truss frame.

Question 77

The weight of a body is due to

A. centripetal force of earth
B. gravitational pull exerted by the earth
C. force of attraction experienced by par-ticles
D. gravitational force of attraction towards the centre of the earth.

Question 78

A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal

A. density of metal can’t be determined
B. metal is twice as dense as water
C. metal will float in water
D. metal is twice as dense as unknown fluid

Question 79

Which of the following is not the unit of work, energy and heat ?

A. kcal
B. kg m
C. kWhr
D. hp

Question 80

If n = number of members andy = number of joints, then for a perfect frame, n =

A. 2j-1
B. 2j-2
C. 2j-3
D. 3j-2

Question 81

The unit of work or energy in S.I. units is

A. newton
B. pascal
C. watt
D. joule.

Question 82

The unit of power in S.I. units is

A. newton meter
B. watt
C. joule
D. kilogram meter/sec.

Question 83

Frictional force encountered after commencement of motion is called

A. post friction
B. limiting friction
C. frictional resistance
D. dynamic friction.

Question 84

The resultant of the following three couples 20 kg force, 0.5 m arm, + ve sense 30 kg force, 1 m arm, – ve sense 40 kg force, 0.25 m arm, + ve sense having arm of 0.5 m will be

A. 20 kg, – ve sense
B. 20 kg, + ve sense
C. 10 kg, + ve sense
D. 10 kg, – ve sense

Question 85

Center of percussion is

A. the point of C.G.
B. the point of metacentre
C. the point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
D. point of suspension

Question 86

Which of the following is not the unit of energy

A. kg m
B. kcal
C. wattr
D. watt hours

Question 87

Two coplanar couples having equal and opposite moments

A. Balance each other
B. Produce a couple and an unbalanced force
C. Are equivalent
D. Produce a moment of couple

Question 88

The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is as per the principle of

A. forces
B. independence of forces
C. balance of force
D. resolution of forces.

Question 89

A body of weight W on inclined plane of a being pulled up by a horizontal force P will be on the point of motion up the plane when P is equal to

A. W
B. W sin (a + \$)
C. Wtan(a + <|))
D. Wan(a-)

Question 90

The magnitude of two forces, which when acting at right angle produce resultant force of VlOkg and when acting at 60° produce resultant of Vl3 kg. These forces are

A. 2 and V6
B. 3 and 1 kg
C. V5 and V5
D. 2 and 5

Question 91

If a rigid body is in equilibrium under the action of three forces, then

A. these forces are equal
B. the lines of action of these forces meet in a point
C. the lines of action of these forces are parallel
D. (B) and (C) above

Question 92

Which of the following is not a scalar quantity

A. mass
B. volume
C. density
D. acceleration.

Question 93

In the lever of third order, load W, effort P and fulcrum F are oriented as follows

A. W between P and F
B. F between W and P
C. P between W and F
D. W, P and F all on one side

Question 94

Which of the following is a vector quantity

A. energy
B. mass
C. momentum
D. angle

Question 95

A number of forces acting at a point will be in equilibrium if

A. Their total sum is zero
B. Two resolved parts in two directions at right angles are equal
C. Sum of resolved parts in any two perpendicular directions are both zero
D. All of them are inclined equally

Question 96

Which of the following is not a vector quantity

A. weight
B. velocity
C. acceleration
D. force

Question 97

The C.G. of a solid hemisphere lies on the central radius 3r

A. at distance — from the plane base 3r
B. at distance — from the plane base 3r
C. at distance — from the plane base 3r
D. at distance — from the plane base or

Question 98

A force acting on a body may

A. introduce internal stresses
B. retard its motion
C. change its motion
D. all of the above.

Question 99

D Alembert’s principle is used for

A. reducing the problem of kinetics to equivalent statics problem
B. determining stresses in the truss
C. stability of floating bodies
D. designing safe structures

Question 100

A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve

A. catenary
B. parabola
C. hyperbola
D. elliptical

Question 101

A cable with a uniformly distributed load per horizontal metre run will take the following shape

A. Straight line
B. Parabola
C. Hyperbola
D. Elliptical

Question 102

Which is the correct statement about law of polygon of forces ?

A. if any number of forces acting at a point can be represented by the sides of a polygon taken in order, then the forces are in equilibrium
B. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium
C. if a polygon representing forces acting at a point is closed then forces are in equilibrium
D. if any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium

Question 103

A pair of smith’s tongs is an example of the lever of

A. zeioth order
B. first order
C. second order
D. third order

Question 104

Which of the following is not the unit of power ?

A. kW (kilowatt)
B. hp (horse power)
C. kg m/sec
D. kcal/kg sec.

Question 105

The effort required to lift a load W on a screw jack with helix angle a and angle of friction

A. Wtan(a + <)>)
B. Wtan(a-<)>)
C. Wcos(a + )
D. Wsin(a + <(>)

Question 106

A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if

A. the floor is smooth, the wall is rough
B. the floor is rough, the wall is smooth
C. the floor and wall both are smooth surfaces
D. the floor and wall both are rough sur-faces

Question 107

According to principle of moments

A. if a system of coplanar forces is in equilibrium, then their algebraic sum is zero
B. if a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
C. the algebraic sum of the moments of any two forces about any point is equal to moment of theiwesultant about the same point
D. positive and negative couples can be balanced

Question 108

Which of the following is not the unit of distance ?

A. angstrom
B. light year
C. millimeter
D. milestone.

Question 109

Which of the following is not the unit of pressure ?

A. kg/cm
B. atmosphere
C. mm of wcl
D. newton.

Question 110

From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the center of circular plate

A. 0.5 cm
B. 1.0 cm
C. 1.5 cm
D. 2.5 cm

Question 111

A framed structure is perfect if it contains members equal to (where n = number of joints in a frame)

A. 2n-3
B. n-l
C. 2n-l
D. n-2