SECTION-6

MACHINE DESIGN MCQ

##### Q51. Which of the following materials is having maximum ratio of the endurance limit to the ultimate tensile strength?

(a) cast steel
(b) cast iron
(c) steel
(d) non-ferrous metals.

Ans:(c) steel

##### Q52. Which of the following materials is having minimum ratio of the endurance limit to the ultimate tensile strength?

(a) cast steel
(b) cast iron
(c) steel
(d) non-ferrous metals.

Ans:(d) non-ferrous metals.

##### Q53. The endurance limit of a material, subjected to fatigue loading

(a) increases with the increase of surface finish
(b) increases with the decrease of surface finish
(c) is independent of surface finish
(d) none of the above.

Ans:(a) increases with the increase of surface finish

##### Q54. Choose the correct statement

(a) Fatigue is the failure of a material above the yield point.
(b) For a mirror polished material, the surface finish factor is 0.5.
(c) Stress concentration factor is independent of the geometry of the machine component.
(d) Endurance limit of a material subjected to fatigue loading depends on the surface finish and ultimate tensile strength of the material.

Ans:(d) Endurance limit of a material subjected to fatigue loading depends on the surface finish and ultimate tensile strength of the material.

##### Q55. When the deformation of a machine number is due to bending only, the maximum bending  moment is given by M = τZ in which

(a) τ is the maximum shear stress and Z is polar modulus of section
(b) τ is the maximum tensile stress and Z is modulus of section
(c) τ is the maximum compressive stress and Z is modulus of section
(d) τ is the maximum tensile or compressive stress and Z modulus of section.

Ans:(d) τ is the maximum tensile or compressive stress and Z modulus of section

##### Q56. When the deformation of a machine member is due to pure torsion only, the maximum torque is given by T = τZ in which

(a) τ is the maximum shear stress and Z is polar modulus of section
(b) τ is the maximum tensile stress and Z modulus of section.
(c) τ is the maximum compressive stress and Z is modulus of section
(d) τ is the maximum tensile or compressive stress and Z modulus of section.

Ans:(a) τ is the maximum shear stress and Z is polar modulus of section

(a) πD3/64
(b)πD3/32
(c)πD3/16
(d) πD4/64

Ans:(c)πD3/16

(a) πD3/64
(b)πD3/32
(c)πD3/16
(d) πD4/64

Ans:(b)πD3/32

(a) πD3/64
(b)πD3/32
(c)πD3/16
(d) πD4/64

Ans:(d) πD4/64

##### Q60. The planes on which maximum shear stress act is given by

(a) tan2θ1= σ1 − σ2/2τ
(b) tan2θ1=τ /2(σ1 − σ2)
(c) tan2θ1=2τ /(σ1 − σ2)
(d) tan2θ1=2τ /(σ1 + σ2)

Ans:(a) tan2θ1= σ1 − σ2/2τ

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##### Read More Sections of Machine Design

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Machine Design MCQ – Section-1

Machine Design MCQ – Section-2

Machine Design MCQ – Section-3

Machine Design MCQ – Section-4

Machine Design MCQ – Section-5

Machine Design MCQ – Section-6

Machine Design MCQ – Section-7