Engineering Materials 14

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Objective Questions and Answer: Engineering Materials 14

Subject: Engineering Materials 14

Part 14: Objective questions and answers of Engineering Materials

 

Q1. The value of shear stress which is induced in the shaft due to the applied couple varies

a) from maximum at the center to zero at the circumference

b) from zero at the center to maximum at the circumference

c) from maximum at the center to mini-mum at the circumference

d) from minimum at the centre to maximum at the circumference

 

Q2. A key is subjected to side pressure as well at shearing forces. These pressures are called

a) bearing stresses

b) fatigue stresses

c) crushing stresses

d) resultant stresses

 

Q3. In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be

a) increase key length

b) increase key depth

c) increase key width

d) double all the dimensions

 

Q4. Shear stress induced in a shaft subjected to tension will be

a) maximum at periphery and zero at center

b) maximum at center

c) uniform throughout

d) none of the above.

 

Q5. Ductility of a material can be defined as

a) ability to undergo large permanent deformations in compression

b) ability to recover its original form

c) ability to undergo large permanent deformations in tension

d) all of the above

 

Q6. Malleability of a material can be defined as

a) ability to undergo large permanent deformations in compression

b) ability to recover its original form

c) ability to undergo large permanent deformations in tension

d) all of the above

 

Q7. In compression, a prism of brittle material will break

a) by forming a bulge

b) by shearing along oblique plane

c) in direction perpendicular to application of load

d) by crushing into thousands of pieces

 

Q8. The ability of a material to resist softening at high temperature is known as

a) creep

b) hot tempering

c) hot hardness

d) fatigue

 

Q9. Mild steel belongs to the following category

a) low carbon steel

b) medium carbon steel

c) high carbon steel

d) alloy steel

 

Q10. The ultimate tensile strength of low carbon steel by working at a high strain rate will

a) decrease

b) increase

c) remain constant

d) first increase and then decrease

 

Q11. Slow plastic deformation of metals under a constant stress is known as

a) creep

b) fatigue

c) endurance

d) plastic deformation

 

Q12. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to l00°C will

a) increase

b) decrease

c) remain same

d) first increase and then decrease

 

Q13. The number of electrons in 1 cm3 of metal would be of the order of

a) 1010

b) TO16

c) 1022

d) 1040

 

Q14. Stress relaxation is- the phenomenon

a) in which parts are not loaded

b) in which stress remains constant on in-creasing load

c) in which deformation tends to loosen the joint and produces a stress reduced

d) stress reduces on increasing load

 

Q15. The elastic stress strain behaviour of rubber is

a) linear

b) non-linear

c) plastic

d) no fixed relationship

 

Q16. Isotropic materials are those which have the same

a) elastic properties in all directions

b) stresses induced in all directions

c) thermal properties in all directions

d) electric and magnetic properties in all directions

 

Q17. Recrystallization temperature is one

a) at which crystals first start forming from molten metal when it is cooled

b) at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated

c) at which change of allotropic form takes place

d) at which crystals grow bigger in size

 

Q18. Points of arrest for iron correspond to

a) stages at which allotropic forms change

b) stages at which further heating does not increase temperature for some time

c) stages at which properties do not change with increase in temperature

d) there is nothing like points of arrest

 

Q19. Delta iron occurs at temperature of

a) room temperature

b) above melting point

c) between 1400°C and 1539°C

d) between 910°C and 1400°C

 

Q20. A material is known as allotropic or polymorphic if it

a) has a fixed structure under all conditions

b) exists in several crystal forms at different temperatures

c) responds to heat treatment

d) has its atoms distributed in a random pattern

 

Part 14: Objective questions and answers of Engineering Materials

 

Q1. Answer b

Q2. Answer a

Q3. Answer c

Q4. Answer d

Q5. Answer c

Q6. Answer a

Q7. Answer b

Q8. Answer b

Q9. Answer a

Q10. Answer b

Q11. Answer a

Q12. Answer a

Q13. Answer c

Q14. Answer c

Q15. Answer b

Q16. Answer a

Q17. Answer b

Q18. Answer a

Q19. Answer c

Q20. Answer b

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