List of 100 Objective Questions On Strength Of Materials For Competitive Exams
1.The intensity of stress which causes unit strain is called
unit stress
bulk modulus
modulus of rigidity
modulus of elasticity
principal stress.
ANSWER : : modulus of elasticity
2.The Young’s modulus of a wire is defined as the stress which will increase the length of wire compared to its original length
half
same amount
double
one-fourth
four times.
ANSWER : : same amount
3.Percentage reduction of area in performing tensile test on cast iron may be of the order of
50%
25%
0%
15%
60%.
ANSWER : : 0%
4.If the radius of wire stretched by a load is doubled, then its Young’s modulus will be
doubled
halved
become four times
become one-fourth
remain unaffected.
ANSWER : : remain unaffected.
5.During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area of cross-section at neck was 0.5 cm2. Ultimate tensile strength of specimen is
4 tonnes/cm2
8 tonnes/cm2
16 tonnes/cm2
22 tonnes/cm2
none of the above.
ANSWER : : 8 tonnes/cm2
6.True stress-strain curve for materials is plotted between
load/original cross-sectional area and change in length/original length
load/instantaneous cross-sectional area original area and log.
load/instantaneous cross-sectional area and change in length/original length
load/instantaneous area and instantaneous area/original area
none of the above.
ANSWER : : load/instantaneous cross-sectional area original area and log.
7.Which is the false statement about true stress-strain method
It does not exist
It is more sensitive to changes in both metallurgical and mechanical conditions
It gives, a more accurate picture of the ductility
It can be correlated with stress-strain values in other tests like torsion, impact, combined stress tests etc.
It can be used for compression tests as well.
ANSWER : : It does not exist
8.It equal and opposite forces applied to a body tend to elongate it, the stress so produced is called
internal resistance
tensile stress
transverse stress
compressive stress
working stress.
ANSWER : : tensile stress
9.In a tensile test on mild steel specimen, the breaking stress as compared to ultimate tensile stress is
more
less
same
more/less depending on composition
may have any value.
ANSWER : : less
10.Modulus of rigidity is defined as the ratio of
longitudinal stress and longitudinal strain
volumetric stress and volumetric strain
lateral stress and lateral strain
shear stress and shear strain
linear stress and lateral strain.
ANSWER : : shear stress and shear strain
11.The value of modulus of elasticity for mild steel is of the order of
2.1xl05 kg/cm2
2.1 X 106 kg/cm2
2.1 x 107 kg/cm2
0.1 xlO6 kg/cm2 (
opt 5
ANSWER : : 2.1 X 106 kg/cm2
12.Deformation per unit length in the direction of force is known as
strain
lateral strain
linear strain
linear stress
unit strain.
ANSWER : : linear strain
13.A thin mild steel wire is loaded by adding loads in equal increments till it breaks. The extensions noted with increasing loads will behave as under
uniform throughout
increase uniformly
first increase and then decrease
increase uniformly first and then in-crease rapidly
increase rapidly first and then uniformly.
ANSWER : : increase uniformly first and then in-crease rapidly
14.The unit of Young’s modulus is
mm/mm
kg/cm
kg
kg/cm2
kg cm2.
ANSWER : : kg/cm2
15.Which of the following materials is most elastic
rubber
plastic
brass
steel
glass.
ANSWER : : steel
16.If a part is constrained to move and heated, it will develop
principal stress
tensile stress
compressive stress
shear stress
no stress.
ANSWER : : compressive stress
17.The ultimate tensile stress of mild steel compared to ultimate compressive stress is
same
more
less
more or less depending on other factors
unpredictable.
ANSWER : : more
18.Hooke’s law holds good upto
yield point
limit of proportionality
breaking point
elastic limit
plastic limit.
ANSWER : : limit of proportionality
19.Young’s modulus is defined as the ratio of
volumetric stress and volumetric strain
lateral stress and lateral strain
longitudinal stress and longitudinal strain
shear stress to shear strain
longitudinal stress and lateral strain.
ANSWER : : longitudinal stress and longitudinal strain
20.The impact strength of a material is an index of its
toughness
tensile strength
capability of being cold worked
hardness
fatigue strength.
ANSWER : : toughness
21.Tensile strength of a material is obtained by dividing the maximum load during the test by the
area at the time of fracture
original cross-sectional area
average of (a) and (b)
minimum area after fracture
none of the above.
ANSWER : : original cross-sectional area
22.Which of the following has no unit
kinematic viscosity
surface tension
bulk modulus
strain
elasticity.
ANSWER : : strain
23.For steel, the ultimate strength in shear as compared to in tension is nearly
same
half
one-third
two-third
one-fourth.
ANSWER : : half
24.The materials having same elastic properties in all directions are called
ideal materials
uniform materials
isotropic materials
practical materials
elastic materials.
ANSWER : : isotropic materials
25.The ratio of lateral strain to the linear strain within elastic limit is known as
Young’s modulus
bulk modulus
modulus of rigidity
modulus of elasticity
Poisson’s ratio.
ANSWER : : Poisson’s ratio.
26.Poisson’s ratio is defined as the ratio of
longitudinal stress and longitudinal strain
longitudinal stress and lateral stress
lateral stress and longitudinal stress
lateral stress and lateral strain
none of the above.
ANSWER : : lateral stress and longitudinal stress
27.The value of Poisson’s ratio for cast iron is
0.1 to 0.2
0.23 to 0.27
0.25 to 0.33
0.4 to 0.6
3 to 4.
ANSWER : : 0.23 to 0.27
28.The property of a material which allows it to be drawn into a smaller section is called
plasticity
ductility
elasticity
malleability
durability.
ANSWER : : ductility
29.The change in the unit volume of a material under tension with increase in its Poisson’s ratio will ,
increase
decrease
remain same
increase initially and then decrease
unpredictable.
ANSWER : : decrease
30.The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight
of same magnitude as that of bar and applied at the lower end
half the weight of bar applied at lower end
half of the square of weight of bar applied at lower end
one-fourth of weight of bar applied at lower end
none of the above.
ANSWER : : half the weight of bar applied at lower end
31.The stress developed in a material at breaking point in extension is called
breaking stress
fracture stress
yield point stress
ultimate tensile stress
proof stress.
ANSWER : : breaking stress
32.In the tensile test, the phenomenon of slow extension of the material, i. e. stress increasing with the time at a constant load is called
creeping
yielding
breaking
plasticity
none of the above.
ANSWER : : creeping
33.If a material expands freely due to heating it will develop
thermal stresses
tensile stress
bending
compressive stress
no stress.
ANSWER : : no stress.
34.Flow stress corresponds to
fluids in motion
breaking point
plastic deformation of solids
rupture stress
none of the above.
ANSWER : : plastic deformation of solids
35.The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight
of same magnitude as that of bar and applied at the lower end
half the weight of bar applied at lower end
half of the square of weight of bar applied at lower end
one-fourth of weight of bar applied at lower end
none of the above.
ANSWER : : half the weight of bar applied at lower end
36.The stress developed in a material at breaking point in extension is called
breaking stress
fracture stress
yield point stress
ultimate tensile stress
proof stress.
ANSWER : : breaking stress
37.In the tensile test, the phenomenon of slow extension of the material, i. e. stress increasing with the time at a constant load is called
creeping
yielding
breaking
plasticity
none of the above.
ANSWER : : creeping
38.If a material expands freely due to heating it will develop
thermal stresses
tensile stress
bending
compressive stress
no stress.
ANSWER : : no stress.
39.Flow stress corresponds to
fluids in motion
breaking point
plastic deformation of solids
rupture stress
none of the above.
ANSWER : : plastic deformation of solids
40.The property of a material by virtue of which a body returns to its original, shape after removal of the load is called
plasticity
elasticity
ductility
malleability
resilience.
ANSWER : : elasticity
41.The property of a material by virtue of which it can be beaten or rolled into plates is called
malleability
ductility
plasticity
elasticity
reliability.
ANSWER : : malleability
42.The buckling load for a given material depends on
slenderness ratio and area of cross-section
Poisson’s ratio and modulus of elasticity
slenderness ratio and modulus of elasticity
slenderness ratio, area of cross-section and modulus of elasticity
Poisson’s ratio and slenderness ratio.
ANSWER : : slenderness ratio, area of cross-section and modulus of elasticity
43.Rupture stress is
breaking stress
maximum load/original cross-section�al area 04)
load at breaking point/A
load at breaking point/neck area
maximum stress.
ANSWER : : load at breaking point/neck area
44.The materials which exhibit the same elastic properties in all directions are called
homogeneous
inelastic
isotropic
isotropic
relativistic.
ANSWER : : isotropic
45.The ratio of direct stress to volumetric strain in case of a body subjected to three mutually perpendicular stresses of equal intensity, is equal to
Young’s modulus
bulk modulus
modulus of rigidity
modulus of elasticity
Poisson’s ratio.
ANSWER : : bulk modulus
46.For which material the Poisson’s ratio is more than unity
steel
copper
aluminum
cast iron
none of the above.
ANSWER : : none of the above.
47.The stress necessary to initiate yielding is
considerably greater than that necessary to continue it
considerably lesser than that necessary to continue it
greater than that necessary to stop it
lesser than that necessary to stop it
equal to that necessary to stop it.
ANSWER : : considerably greater than that necessary to continue it
48.In question 56, the internal reaction in bottom 80 cm length will be
same in both cases
zero in first case
different in both cases
data are not sufficient to determine same
none of the above.
ANSWER : : zero in first case
49.The stress at which extension of the material takes place more quickly as com�pared to the increase in load is called
elastic point of the material
plastic point of the material
breaking point of the material
yielding point of the material
ultimate point of the material.
ANSWER : : yielding point of the material
50.When it is indicated that a member is elastic, it means that when force is applied, it will
not deform
be safest
stretch
not stretch
none of the above.
ANSWER : : stretch
51.The percentage reduction in area of a cast iron specimen during tensile test would be of the order of
more than 50%
25�50%
10�25%
5�10%
negligible.
ANSWER : : negligible.
52.The elasticity of various materials is controlled by its
ultimate tensile stress
proof stress
stress at yield point
stress at elastic limit
tensile stress.
ANSWER : : stress at elastic limit
53.In a tensile test, near the elastic limit zone, the
tensile strain increases more quickly
tensile strain decreases more quickly
tensile strain increases in proportion to the stress
tensile strain decreases in proportion to the stress
tensile strain remains constant.
ANSWER : : tensile strain increases more quickly
54.The force acting along the circumference will cause stress in the walls in a direction normal to the longitudinal axis of cylinder; this stress is called
longitudinal stress
hoop stress
yeiled stress
ultimate stress
none of the above.
ANSWER : : hoop stress
55.A riveted joint in which every rivet of a row is opposite to other rivet of the outer row, is known as
chain riveted joint
diamond riveted joint
cross-cross riveted joint
zig-zag riveted joint
none of the above.
ANSWER : : chain riveted joint
56.Efficiency of a riveted joint is the ratio of its strength (max. load it can resist without failure) to the strength of the unpunished plate in
tension
compression
bearing
any one of the above
none of the above.
ANSWER : : tension
57.A cylindrical section having no joint is known as
joint less section
homogeneous section
perfect section
manufactured section
seamless section.
ANSWER : : seamless section.
58.A riveted joint in which the number otrivets decrease from innermost to outer most row is called
chain riveted joint
diamond riveted joint
cross-cross riveted joint
zig-zag riveted joint
none of the above.
ANSWER : s: b
59.Proof resilience per material is known as
resilience
proof resilience
modulus of resilience
toughness
impact energy.
ANSWER : : modulus of resilience
60.The distance between the centers of the rivets in adjacent rows of zig-zag riveted joint is known as
pitch
back pitch
diagonal pitch
diametral pitch
lap.
ANSWER : : diagonal pitch
61.The strain energy stored in a body due to suddenly applied load compared to when it is applied gradually is
same
twice
four times
eight times
half.
ANSWER : : four times
62.A material capable of absorbing large amount of energy before fracture is known as
ductility
toughness
resilience
shock proof
plasticity.
ANSWER : : toughness
63.A non-yielding support implies that the
support is frictionless
support can take any amount of reaction
support holds member firmly
slope of the beam at the support is zero
none of the above.
ANSWER : : slope of the beam at the support is zero
64.If the rivets in adjacent rows are staggered and the outermost row has only one rivet, the arrangement of the rivets is called
chain riveting
zig zag riveting
diamond riveting
cross-cross riveting
none of the above.
ANSWER : : diamond riveting
65.Diamond riveted joint can be adopted in the case of following type of joint
butt joint
lap joint
double riveted lap joints
all types of joints
none of the above.
ANSWER : : butt joint
66.Rivets are made of following type of material
tough
hard
resilient
ductile
malleable.
ANSWER : : ductile
67.The stress induced in a body due to suddenly applied load compared to when it is applied gradually is
same
half
two times
four times
none of the above.
ANSWER : : two times
68.The maximum strain energy that can be stored in a body is known as
impact energy
resilience
proof resilience
modulus of resilience
toughness.
ANSWER : : proof resilience
69.The ratio of elongation in a prismatic bar due to its own weight (W) as compared to another similar bar carrying an additional weight (W) will be
1:2
1 : 3
1 : 4
1 : 2.5
1 : 2.25.
ANSWER : : 1 : 3
70.The total strain energy stored in a body is termed as
resilience
proof resilience
modulus of resilience
toughness
impact energy.
ANSWER : : resilience
71.In a prismatic member made of two materials so joined that they deform equal�ly under axial stress, the unit stresses in two materials ar equal
proportional to their respective moduli of elasticity
inversely proportional to their moduli of elasticity
average of the sum of moduli of elasticity
none of the above.
ANSWER : : proportional to their respective moduli of elasticity
72.A boiler shell 200 cm diameter and plate thickness 1.5 cm is subjected to internal pressure of 1.5 MN/m , then the hoop stress will be
30 MN/m2
50 MN/m2
100 MN/m2
200 MN/m2
300 MN/m2.
ANSWER : : 100 MN/m2
73.A beam is loaded as cantilever. If the load at the end is increased, the failure will occur in the middle
at the tip below the load
at the support
anywhere
none of the above.
ANSWER : : anywhere
74.The ratio of elongation in a prismatic bar due to its own weight (W) as compared to another similar bar carrying an additional weight (W) will be
1:2
1 : 3
1 : 4
1 : 2.5
1 : 2.25.
ANSWER : : 1 : 3
75. The total strain energy stored in a body is termed as
resilience
proof resilience
modulus of resilience
toughness
impact energy.
ANSWER : : resilience
76.In a prismatic member made of two materials so joined that they deform equal�ly under axial stress, the unit stresses in two materials are equal
proportional to their respective moduli of elasticity
inversely proportional to their moduli of elasticity
average of the sum of moduli of elasticity
none of the above.
ANSWER : : proportional to their respective moduli of elasticity
77.A boiler shell 200 cm diameter and plate thickness 1.5 cm is subjected to internal pressure of 1.5 MN/m , then the hoop stress will be
30 MN/m2
50 MN/m2
100 MN/m2
200 MN/m2
300 MN/m2.
ANSWER : : 100 MN/m2
78.A beam is loaded as cantilever. If the load at the end is increased, the failure will occur
in the middle
at the tip below the load
at the support
anywhere
none of the above.
ANSWER : : anywhere
79.The deformation of a bar under its own weight compared to the deformation of same body subjected to a direct load equal to weight of the body is
same
double
half
four times
one-fourth.
ANSWER : : half
80.Resilience of a material is considered when it is subjected to
frequent heat treatment
fatigue
creep
shock loading
resonant condition.
ANSWER : : shock loading
81.When two plates are butt together and riveted with cover plates with two rows of rivets, the joi;it is known as
lap point
butt joint
single riveted single cover butt joint
double riveted double cover butt joint
single riveted double cover butt joint.
ANSWER : : double riveted double cover butt joint
82.The weakest section of a diamond riveting is the section which passes through
the first row
the second row
the central row
one rivet hole of the end row
none of the above.
ANSWER : : one rivet hole of the end row
83.In riveted boiler joints, all stresses, shearing, bearing and tensile are based on the
size of rivet
size of the drilled or reamed hole
average of size of rivet and hole
smaller of the two
any one of the above.
ANSWER : : size of the drilled or reamed hole
84.The safe twisting moment for a compound shaft is equal to the
maximum calculated value
minimum calculated value
mean value
extreme value
none of the above.
ANSWER : : minimum calculated value
85.Shear stress induced in a shaft subjected to tension will be
maximum at periphery and zero at center
maximum at center
uniform throughout
average value in center
none of the above.
ANSWER : : none of the above.
86.The torsional rigidity of a shaft is expressed by the
maximum torque it can transmit
number of cycles it undergoes before failure
elastic limit upto which it resists torsion, shear and bending stresses
torque required to produce a twist of one radian per unit length of shaft
maximum power it can transmit at highest possible-speed.
ANSWER : : torque required to produce a twist of one radian per unit length of shaft
87.In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be
increase key length
increase key depth
increase key width
double all the dimensions
none of the above.
ANSWER : : increase key width
88.A key is subjected to side pressure as well at shearing forces. These pressures are called
bearing stresses
fatigue stresses
crushing stresses
resultant stresses
none of the above.
ANSWER : : bearing stresses
89.The value of shear stress which is induced in the shaft due to the applied couple varies
from maximum at the centre to zero at the circumference
from zero at the centre to maximum at the circumference
from maximum at the centre to mini-mum at the cricumference
from minimum at the centre to maxi-mum at the circumference
none of the above.
ANSWER : : from zero at the centre to maximum at the circumference