# Strength of Materials MCQs Practice Set

1.Whenever some external system of forces acts on a body, it undergoes some deformation. As the body undergoes some deformation, it sets up some resistance to the deformation. This resistance per unit area to deformation, is called

- strain
- stress (correct)
- pressure
- modulus of elasticity

2.The deformation per unit length is called

- tensile stress
- compressive stress
- shear stress
- strain (correct)

3.The unit of strain is

- N-mm
- N/mm
- mm
- no unit (correct)

4.When a body is subjected to two equal and opposite pulls, as a result of which the body tends to extend its length, the stress and strain induced is

- compressive stress, tensile strain
- tensile stress, compressive strain
- tensile stress, tensile strain (correct)
- compressive stress, compressive strain

5.When a body is subjected to two equal and opposite forces, acting tangentially across the resisting section, as a result of the body tends to shear off across the section, the stress and strain induced is

- tensile stress, tensile strain
- compressive stress, compressive strain
- shear stress, tensile strain
- shear stress , shear strain (correct)

6.Hook’s law holds good up to

- yield point
- elastic limit (correct)
- plastic limit
- breaking point

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

- Equal to
- directly proportional to (correct)
- inversely proportional to

8.The ratio of linear stress to the linear strain is called

- modulus of rigidity
- modulus of elasticity (correct)
- bulk modulus
- poisson’s ratio

9.The unit of modulus of elasticity is same as those of

- stress, strain and pressure
- stress, force and modulus of rigidity
- strain ,force and pressure
- stress, pressure and modulus of rigidity (correct)

10.When change in length takes place, the strain is known as

linear strain (correct)

lateral strain

volumetric strain

shear strain

11.The change in length due to a tensile or compressive force acting on a body is given by

P.l.A/E

Pl/AE (Ans)

E/P.l.A

AE/Plwhere p=Tensile or compressive force acting on the bodyl= Original length of the body,A= Cross-sectional area of the body, andE= Young’s modulus for the material of the body.

12.Young’s modulus may be defined as the ratio of

linear stress to lateral strain

lateral strain to linear strain

linear stress ti linear strain (Ans)

shear stress to shear strain

13.Modulus of rigidity may be defined as the ratio of

linear stress to lateral strain

lateral strain to linear strain

linear stress ti linear strain

shear stress to shear strain (Ans)

14.The deformation of a bar under its own weight is ………………. the deformation, if the same body is subjected to a direct load equal to weight of the body.

Equal to

half (Ans)

double

quadruple

15.The elongation of a conical bar under its own weight is ……………. that of prismatic bar of the same length.

Equal to

half

one-third (Ans)

two-third

16.Strain rosetters are used to

measure shear strain

measure linear strain (Ans)

measure volumetric strain

relieve strain

17.A bar of length L metres extends by l mm under a tensile force of P. The strain produced in the bar is

l/L

0.1l/L

0.01l/L

0.001l/L (Ans)

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

smaller end (Ans)

larger end

middle

anywhere

19. Modular ratio of the two materials is the ratio of

linear stress to linear strain

shear stress to shear strain

their modulus of elasticities (Ans)

their modulus of rigidities

20.The shear modulus of most materials with respect to the modulus of elasticity is

equal to half

less than half (Ans)

more than half

none of these

21.A rod is enclosed centrally in a tube and the assembly is tightened by rigid washers. If the assembly is subjected to a compressive load, then

rod is under compressive

tube is under compressive

both rod and tube are under compression (Ans)

tube is under tension and rod is under compression

22.A bolt is made to pass through a tube and both of them are tightly fitted with the help of washers and nuts. If the nut is tightened, then

bolt and tube are under tension

bolt and tube are under compression

bolt is under compression and tube is under tension

bolt is under tension and tube is under compression (Ans)

23.When a bar is subjected to a change of temperature and its deformation is prevented, the stress induced in the bar is

- tensile stress
- compressive stress
- shear stress
- thermal stress (Ans)

24.Which of the following statement is correct?

The stress is the pressure per unit area

the strain is expressed in mm

hook’s law holds good up to the breaking point

stress is directly proportional to strain within elastic limit (Ans)

25.The unit of stress in S.I. Units is

N/mm^{2}

kN/mm^{2}

N/m^{2}

any one of these (Ans)

26.The modulus of elasticity for mild steel is approximately equal to

10kN/mm^{2}

80kN/mm^{2}

100kN/mm^{2}

210kN/mm^{2 }(Ans)

27.When a bar of length l and diameter d is rigidly fixed at the upper end and hanging freely, then the total elongation produced in the bar due to its own weight is

wl/2E

wl^{2}/2E (Ans)

wl^{3}/2E

wl^{4}/2E

28.The length of a conical bar is l, diameter of base is d and weight per unit volume is w.It is fixed at its upper end and hanging freely.The elongation of the bar under the action of its own weight will be

wl^{2}/2E

wl^{2}/4E

wl^{2}/6E (Ans)

wl^{2}/8E

29.A steel bar of 5 mm is heated from 15^{o}C to 40^{o}C and it is free to expand.The bar will induce

no stress (Ans)

shear stress

tensile stress

compressive stress

30.When a bar is cooled to -5^{o}C, it will develop

no stress

shear stress

tensile stress (Ans)

compressive stress

31.A bar of copper and steel form a composite system, which is heated to a temperature of 40^{o}C. The stress induced in the copper bar will be

tensile

compressive (Ans)

shear

zero

32.The deformation of the bar per unit length in the direction of the force is known as

linear strain (Ans)

lateral strain

volumetric strain

shear strain

33.Every direct stress is always accompanied by a strain in its own direction and an opposite kind of strain in every direction, at right angles to it.Such a strain is known as

linear strain

lateral strain (Ans)

volumetric strain

shear strain

34.The ratio of the lateral strain to the linear strain is called

modulus of elasticity

modulus of rigidity

bulk modulus

poisson’s ratio (Ans)

35.The poisson’s ratio for steel varies from

0.23 to 0.27 (Ans)

0.25 to 0.33

0.31 to 0.34

0.32 to 0.42

36.The poisson’s ratio for cast iron varies from

0.23 to 0.27

0.25 to 0.33 (Ans)

0.31 to 0.34

0.32 to 0.42

37.When a bar of length l, width b and thickness t is subjected to a pullof p, its

length, width and thickness increases

length, width and thickness decreases

length increases, width and thickness decreases (Ans)

length decreases, width and thickness increases

38.The ratio of change in volume to the original volume is called

linear strain

lateral strain

volumetric strain (Ans)

poisson’s ratio

39.When a bar of length l, width b and thickness t is subjected to a push of p, its

length, width and thickness increases

length, width and thickness decreases

length increases, width and thickness decreases

length decreases, width and thickness increases (Ans)

40.The volumetric strain is the ratio of the

original thickness to the change in thickness

change in thickness to the original thickness

original volume to the change in volume

change in volume to the original volume (Ans)

41.When a body is subjected to three mutually perpendicular stresses, of equal intensity, the ratio of direct stress to the corresponding volumetric strain is known as

Young’s modulus

modulus of rigidity

bulk modulus (Ans)

Poisson’s ratio

42.The relation between Young’s modulus (E) and bulk modulus (K) is given by

K=3m-2/mE

K=mE/3m-2

K=3(m-2)/mE

K=mE/3(m-2) (Ans)

43.The ratio of bulk modulus to Young’s modulus for a Poisson’s ratio of 0.25 will be

1/3

2/3 (Ans)

1

3/2

44.The relation between Young’s modulus (E), shear modulus (C) and bulk modulus (K) is given by

E=3K.C/3K+C

E=6K.C/3K+C

E=9K.C/3K+C (Ans)

E=12K.C/3K+C

45.The relation between modulus of elasticity (E) and modulus of rigidity (C) is given by

C=mE/2(m+1) (Ans)

C=2(m+1)/mE

C=2mE/m+1

C=m+1/2mE

46.The ratio of shear modulus to the modulus of elasticity for a Poisson’s ratio of 0.4 will be

5/7

7/5

5/14 (Ans)

14/5

47.If the modulus of elasticity for a given material is twice its modulus of rigidity, then bulk modulus is equal to

2C

3C

2C/3 (Ans)

3C/2

48.The Young’s modulus of a material is 125 Gpa and Poisson’s ratio is 0.25.The modulus of rigidity of the material is

30 Gpa

50 Gpa (Ans)

80 Gpa

100 Gpa

49.Within elastic limit, shear stress is…………….shear strain

equal to

less than

directly proportional to (Ans)

inversely proportional to

50.Shear modulus is the ratio of

linear stress to linear strain

linear stress to lateral strain

volumetric strain to linear strain

shear stress to shear strain (Ans)

51.A localized compressive stress at the area of contact between two members is known as

tensile stress

bending stress

crushing stress (Ans)

shear stress

52.The maximum diameter of the hole that can be punched from a plate of maximum shear stress 1/4^{th} of its maximum crushing stress of punch, is equal to

t

2t

4t (Ans)

8twhere t=thickness of the plate.

53.In the above question, the normal stress on an oblique section will be maximum, when θ is equal to

0^{o }(Ans)

30^{o}

45^{o}

90^{o}

54.When a body is subjected to a direct tensile stress (ϭ) in one plane, then maximum normal stress occurs at a section inclined at………..to the normal of the section

0^{o }(Ans)

30^{o}

45^{o}

90^{o}

55. When a body is subjected to a direct tensile stress (ϭ) in one plane, then maximum shear stress is…………………..the maximum normal stress

equal to

one-half (Ans)

two-third

twice

56.The maximum shear stress is………the algebraic difference of maximum and minimum normal stresses.

equal to

one-half (Ans)

one-fourth

twice

57. Mohr’s circle is used to determine the stresses on an oblique section of a body subjected to

direct tensile stress in one plane accompanied by a shear stress

direct tensile stress in two mutually perpendicular directions

direct tensile stress in two mutually perpendicular directions accompanied by a simple shear stress

all of the above (Ans)

58.The extremeties of any diameter on Mohr’s circle represent

principle stresses

normal stresses on planes at 45^{o }(Ans)

shear stresses on planes at 45^{o}

normal and shear stresses on plane

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

resilience

proof resilience

strain energy (Ans)

impact energy

60.The total strain energy stored in a body is termed as

resilience (Ans)

proof resilience

modulus of resilience

impact energy

61.Strain energy is the

energy stored in a body when strained within elastic limits (Ans)

energy stored in a body when strained upto the breaking of a specimen

maximum strain energy which can be stored in a body

proof resilience per unit volume of a material

62.The strain energy stored in a body, when suddenly loaded, is………….the strain energy stored when same load is applied gradually.

Equal to

one-half

twice

four times (Ans)

63.Resilience is the

energy stored in a body when strained within elastic limits (Ans)

energy stored in a body when strained upto the breaking of a specimen

maximum strain energy which can be stored in a body

none of the above (Ans)

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

Equal to

one-half

twice(Ans)

four times

65.The strain energy stored in a spring, when subjected to maximum load, without suffering permanent distortion, is known as

impact energy

proof resilience (Ans)

proof stress

modulus of resilience

66.The capacity of a strained body for doing work on the removal of the straining force, is called

strain energy

resilience (Ans)

impact energy

proof resilience

67.A beam which is fixed at one end and free at the other is called

simply supported beam

fixed beam

overhanging beam

cantilever beam (Ans)

68.A beam extending beyond the supports is called

simply supported beam

fixed beam

overhanging beam (Ans)

cantilever beam

69.A beam encastered at both the ends is called

simply supported beam

fixed beam (Ans)

continuous beam

cantilever beam

70.A beam supported on more than two supports is called

simply supported beam

fixed beam

overhanging beam (Ans)

continuous beam

71.A cantilever beam is one which is

fixed at both ends

fixed at both ends and free at the other end (Ans)

supported at its ends

supported on more than two supports

72.A continuous beam is one which is

fixed at both ends

fixed at both ends and free at the other end

extending beyond the supports

supported on more than two supports (Ans)

73.A concentrated load is one which

acts at a point on a beam (Ans)

spreads non-uniformly over the whole length of beam

spreads uniformly over the whole length of beam

varies uniformly over the whole length of beam

74.The bending moment on a section is maximum where shear force is

minimum

maximum

changing sign (Ans)

zero

75.When a load on the free end of a cantilever beam is increased, failure will occur

at the free end

at the fixed end (Ans)

in the middle of the beam

at a distance 2l/3 from free end

76.The bending moment at the free end of a cantilever beam is

zero (Ans)

minimum

maximum

77.The shear force of a cantilever beam of length l carrying a uniformly distributed load of w per unit length is…………… at the free end

zero (Ans)

wl/4

wl/2

wl

78.The shear force of a cantilever beam of length l carrying a uniformly distributed load of w per unit length is…………… at the fixed end

zero

wl/4

wl/2

wl (Ans)

79. The shear force diagram of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length will be

a right angled triangle (Ans)

an issoscles triangle

an equilateral triangle

a rectangle

80.The bending moment of a cantilever beam of length l carrying a uniformly distributed load of w per unit length is…………… at the free end

zero (Ans)

wl/4

wl/2

wl

81.The shear force and bending moment are zero at the free end of a cantilever beam, if it carries a

point load at the free end

point load at the middle of its length

uniformly distributed load over the whole length (Ans)

none of the above

82.The bending moment of a cantilever beam of length l carrying a uniformly distributed load of w per unit length is…………… at the fixed end

wl/4

wl/2

wl

wl^{2}/2 (Ans)

83.The shear force diagram for a cantilever beam of length l and carrying a gradually varying load from zero at free end and w per unit length at the fixed end is a

horizontal straight line

vertical straight line

inclined line

parabolic curve (Ans)

84.The shear force of a cantilever beam of length l and carrying a gradually varying load from zero at the free end and w per unit length at the fixed end is ………………..at the fixed end

zero (Ans)

wl/4

wl/2 (Ans)

wl

85.The bending moment of a cantilever beam of length l and carrying a gradually varying load from zero at the free end and w per unit length at the fixed end is ………………..at the fixed end

wl/2

wl

wl^{2}/2

wl^{2}/6 (Ans)

86.The maximum bending moment of a simply supported beam of span l and carrying a point load W at the centre of beam, is

wl/4 (Ans)

Wl/2

Wl

Wl^{2}/4

87.The bending moment diagram for a simply supported beam loaded in its centre is

a right angled triangle

an issoscles triangle (Ans)

an equilateral triangle

a rectangle

88.The shear force diagram for a simply supported beam carrying a uniformly distributed load of w per unit length, consists of

one right angled triangle

two right angled triangles (Ans)

one equilateral triangle

two equilateral triangles

89.The bending moment diagram for a simply supported beam carrying a uniformly distributed load of w per unit length, will be

a horizontal line

a vertical line

an inclined line

a parabolic curve (Ans)

90.The shear force at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per metre at the centre is wl/4

zero (Ans)

wl/4

wl/2

wl^{2}/2

91.The point of contraflexure is a point where

shear force changes sign

bending moment changes sign (Ans)

shear force is maximum

bending moment is maximum

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

zero

minimum

maximum (Ans)

infinity

93.In a simply supported beam carrying a uniformly distributed load w per unit length, the point of contraflexure

lies in the centre of the beam

lies at the ends of the beam

depends upon the length of beam

does not exist

94.When there is a sudden increase or decrease in shear force diagram between any two points, it indicates that there is a

point load at the two points (Ans)

no loading between the two points

uniformly distributed load between the two points

uniformly varying load between the two points

95.When the shear force diagram is a parabolic curve between two points, it indicates that there is a

point load at the two points

no loading between the two points

uniformly distributed load between the two points

uniformly varying load between the two points (Ans)

96.In a beam where shear force changes sign, the bending moment will be

zero

minimum

maximum (Ans)

infinity

97.The point of contraflexure occurs in

cantilever beams

simply supported beams

overhanging beams (Ans)

fixded beams

98.The bending moment at a section tends to bend or deflect the beam and the internal stresses resist its bending.The resistance offered by the internal stresses, to the bending, is called

compressive stress

shear stress

bending stress (Ans)

elastic modulus

99.The assumption, generally, made in the theory of simple bending is that

the beam material is perfectly homogeneous and isotropic

the beam material is stressed within its elastic limit

the plane sections before bending remain plane after bending

all of the above (Ans)

100.In a simple bending theory, one of the assumption is that the material of the beam is isotropic.The assumptiom means that the

normal stress remains constant in all dorections

normal stress varies linearly in the material

elastic constant are same in all the directions (Ans)

elastic constant varies linearly in the material

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

linearly (Ans)

parabolically

hyperbolically

elliptically

102.In a simple bending theory, one of the assumption is that the plane sections before bending remain plane after bending. This assumption means that

stress is uniform throughout the beam

strain is uniform throughout the beam

stress is proportional to the distance from the neutral axis

strain is proportional to the distance from the neutral axis (Ans)

103.When a beam is subjected to a bending moment, the strain in a layer is …………. the distance from the neutral axis.

Equal to

directly proportional to (Ans)

inversely proportional to

independent of

104.The bending equation is

M/I=Ϭ/y=E/R (Ans)

T/J=τ/r=Cθ/l

M/y= Ϭ/I=E/R

T/r= τ/J=Cθ/l

105.A section of beam is said to be in pure bending, if it is subjected to

constant bending moment and constant shear force

constant shear force and zero bending moment

constant bending moment and zero shear force (Ans)

none of the above

106.When a beam is subjected to bending moment, the stress at any point is …………. the distance of the point from the neutral axis.

Equal to

directly proportional to (Ans)

inversely proportional to

independent of

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

zero (Ans)

minimum

maximum

infinity

108.The section modulus (Z) of a beam is given by

I/y (Ans)

I.y

y/I

M/I

109.The section modulus of a rectangular section about an axis through its C.G., is

b/2

d/2

bd^{2}/2

bd^{2}/6 (Ans)

110.The bending stress in a beam is ……………… section modulus.

Directly proportional to

inversely proportional to (Ans)

111.The section modulus of a circular section about an axis through its C.G., is

πd^{2}/4

πd^{2}/16

πd^{3}/16

πd^{3}/32 (Ans)

112.A square beam and a circular beam have the same length, same allowable stress and the same bending moment. The ratio of weight of the square beam to the circular beam is

1/2

1

1/1.12 (Ans)

1/√2

113.For a given stress, the ratio of moment of resistance if a beam of square cross-section when placed with its two sides horizontal to the moment of resistance with its diagonal horizontal, is

1/2

1

1/√2

√2 (Ans)

114.Two beams, one of circular cross section and the other of square cross section, have equal areas of cross-sections. When these beams are subjected to bending,

both beams are equally economical

square beam is more economical (Ans)

circular beam is more economical

none of these

115.When a cantilever beam is loaded at its free end, the maximum compressive stress shall develop at

bottom fibre (Ans)

top fibre

neutral axis

centre of gravity

116.A beam of uniform strength may be obtained by

keeping the width uniform and varying the depth

keeping the depth uniform and varying the width

varying the width and depth both

any one of the above (Ans)

117.If the depth is kept constant for a beam of uniform strength, then its width will vary in proportional to

M (Ans)

√M

M^{2}

M^{3}Where M=Bending moment

118.A beam of uniform strength has

same cross-section throughout the beam

same bending stress at every section (Ans)

same bending moment at every section

same shear stress at every section

119.The bending stress in a beam is ……….. bending moment

equal to

less than

more than

directly proportional to (Ans)

120.At the neutral axis of a beam

the layers are subjected to maximum bending stress

the layers are subjected to minimum bending stress

the layers are subjected to compression

the layers do not undergo any strain ( Ans)

121.The neutral axis of a beam is subjected to ………… stress.

Zero (Ans)

maximum tensile

minimum tensile

maximum compressive

122.The neutral axis of a transverse section of a beam passes through the centre of gravity of the section and is

in the vertical plane

in the horizontal plane

in the same plane in which the beam bends(Ans)

123.In a beam subjected to pure bending, the intensity of stress in any fibre is ……….. the distance of the fibre from the neutral axis

equal to

less than

more than

directly proportional (Ans)

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

Same

double

four times (Ans)

six times

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

Same

double (Ans)

four times

six times

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

Same

one-half (Ans)

one-fourth

one-eighth

127.When a rectangular beam is loaded transversely, the maximum tensile stress is developed on the

top layer (Ans)

bottom layer

neutral axis

every cross-section

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

top layer

bottom layer (Ans)

neutral axis

every cross-section

129.At the neutral axis of a beam, the shear stress is

zero

minimum

maximum (Ans)

infinity

130.the maximum shear stress developed in a beam of rectangular section is …………. the average shear stress.

Equal to

4/3 times

1.5 times (Ans)

twice

131.The maximum shear stress developed in a beam of circular section is …………. the average shear stress.

Equal to

4/3 times (Ans)

1.5 times

twice

132.The ratio of maximum shear stress developed in a rectangular beam and a circular beam of the same cross-section area is

2/3

3/4

1

9/8 (Ans)

133.A beam of triangular section is placed with its base horizontal. The maximum shear stress occurs at

apex of the triangle

mid of the height (Ans)

centre of gravity of the triangle

base of the triangle

134.A base of T-section is subjected to a shear force of F. The maximum shear force will occur at the

top of the section

bottom of the section

neutral axis of the section (Ans)

junction of web and flange

135. A flitched beam is used to

change the shape of the beam

effect the saving in material

equalize the strength in tension and compression (Ans)

increase the cross-section of the beam

136.A rectangular beam of length l supported at its two ends carries a central point load W.The maximum deflection occurs

at the ends

at l/3 from both ends

at the centre (Ans)

none of these

137.The maximum deflection of a cantilever beam of length l with a point load W at the free end is

Wl^{3}/3EI (Ans)

Wl^{3}/8EI

Wl^{3}/16EI

Wl^{3}/48EI

138.The maximum deflection of a cantilever beam of length l with a uniformly distributed load of w per unit length is

Wl^{3}/3EI (Ans)

Wl^{3}/8EI

Wl^{3}/16EI

Wl^{3}/48EIwhere W=wl

139. The maximum deflection of a fixed beam carrying a central point load lies at

fixed ends

centre of beam (Ans)

l/3 from fixed ends

none of these

140.The maximum deflection of a fixed beam of length l carrying a central point load W is

Wl^{3}/48EI

Wl^{3}/96EI

Wl^{3}/192EI (Ans)

Wl^{3}/384EI

141.The maximum deflection of a fixed beam of length l carrying a total load W uniformly distributed over the whole length is

Wl^{3}/48EI

Wl^{3}/96EI

Wl^{3}/192EI

Wl^{3}/384EI (Ans)

142.The product of the tangential force acting on the shaft and its distance from the axis of the shaft(i.e. Radius of shaft) is known as

bending moment

twisting moment (Ans)

torsional rigidity

flexural rigidity

143.When a shaft is subjected to a twisting moment, every cross-section of the shaft will be under

tensile stress

compressive stress

shear stress (Ans)

bending stress

144.The shear stress at the centre of a circular shaft under torsion is

zero (Ans)

minimum

maximum

infinity

145.The shear stress at the outermost fibres of a circular shaft under torsion is

zero

minimum

maximum (Ans)

infinity

146.The torsional rigidity of a shaft is given by

- T/J
- T/θ (Ans)
- T/r
- T/G

147.When a shaft is subjected to torsion, the shear stress induced in the shaft varies from

- minimum at the centre to maximum at the circumference
- maximum at the centre to maximum at the circumference
- zero at the centre to maximum at the circumference (Ans)
- maximum at the centre to zero at the circumference

148.For a shaft, the shear stress at a point is…………….the distance from the axis of the shaft

- equal to
- directly proportional to (Ans)
- inversely proportional to

149.The polar moment of inertia of a solid circular shaft if diameter(D) is

- πD
^{3}/16 - πD
^{3}/32 - πD
^{4}/32 (Ans) - πD
^{4}/64

150.The polar moment of inertia of a follow shaft of outer diameter(D)

and inner diameter (d) is

- π/16(D
^{3 –}d^{3}) - π/16(D
^{4 –}d^{4}) (Ans) - π/16(D
^{4 –}d^{4}) (Ans) - π/16(D
^{4 }– d^{4})

151.Which of the following is the correct torsion equation?

- M/I=Ϭ/y=E/R
- T/J=τ/R=Cθ/l (Ans)
- M/R= T/J=Cθ/l
- T/l= τ/J=R/Cθ

152.The torque transmitted by a solid shaft of diameter(D) is

- π/4* τ*D
^{3} - π/16* τ*D
^{3} - π/32* τ*D
^{3} - π/64* τ*D
^{3}

Where τ=Maximum allowable shear stress

153.Two solid shafts ‘A’ and ‘B’ are made of the same material.The shaft ‘A’ is of 50 mm diameter and shaft ‘B’ is of 100 mm diameter. The strength of shaft ‘B’ is……………as that of shaft A.

One-half

double

four times

eight times (Ans)

154.In the torsion equation T/J=τ/R=Cθ/l, the term J/R is called

shear modulus

section modulus

polar modulus (Ans)

none of these

155.The polar modulus for a solid shaft of diameter(D) is

πD^{2}/4

πD^{3}/16 (Ans)

πD^{3}/32

πD^{4}/64

156.The polar modulus for a follow shaft of outer diameter(D)

and inner diameter (d) is

- π/4(D
^{2}– d^{2}/D) - π/16(D
^{3 –}d^{3}/D) - π/16(D
^{4 –}d^{4}/D) (Ans) - π/32(D
^{4 –}d^{4}/D)