Engineering Materials objective questions with answers part3

Q1. Dislocations in materials refer to the following type of defect
(A) point defect
(B) line defect
(C) volumetric defect
(D) chemical defect.

Q2. An example of amorphous material is
(A) zinc
(B) lead
(C) silver
(D) glass

Q3. Which is false statement about tempering? Tempering is done to
(A) improve machinability
(B) improve ductility
(C) improve toughness
(D) reduce hardness and brittleness.

Q4. Which is false statement about case hardening. Case hardening is done by
(A) electroplating
(B) cyaniding
(C) induction hardening
(D) flame hardening.

Q5. Which of the following is the binding material in cemented carbides
(A) cobalt
(B) nickel
(C) vanadium
(D) iron

Q6. Chromium in steel
(A) improves wear resistance, cutting ability and toughness
(B) refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
(C) improves cutting ability and reduces hardenability
(D) gives ductility, toughness, tensile strength and anticorrosion properties

Q7. Manganese in steel increases its
(A) tensile strength
(B) hardness
(C) ductility
(D) malleability.

Q8. Cemented carbide tools are not found to be suitable for cutting
(A) brass
(B) cast iron
(C) aluminium
(D) steel

Q9. Sulphur in steel
(A) acts as deoxidiser
(B) reduces the grain size
(C) decreases tensile strength and hardness
(D) lowers the toughness and transverse ductility

Q10. Tungsten in steel
(A) improves wear resistance, cutting ability and toughness
(B) refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
(C) improves cutting ability and reduces hardenability
(D) gives ductility, toughness, tensile strength and anticorrosion properties

Q11. Ductility of a material can be defined as the ability to
(A) undergo large permanent deformations in compression
(B) recover its original form
(C) undergo large permanent deformations in tension
(D) all of the above

Q12. Malleability of a material is the ability to
(A) undergo large permanent deformations in compression
(B) recover its original form
(C) undergo large permanent deformations in tension
(D) all of the above

Q13. 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

Q14. The ability of a material to resist softening at high temperature is known as
(A) creep
(B) hot tempering
(C) hot hardness
(D) superhardening.

Q15. Mild steel belongs to the following category
(A) low carbon steel
(B) medium carbon steel
(C) high carbon steel
(D) alloy steel

Q16. The ultimate tensile strength of low carbon steel by working at a high strain rate will
(A) decrease
(B) increase
(C) first increase and then decrease
(D) first decrease and then increase.

Q17. Slow plastic defomiation of metals under a constant stress is known as
(A) creep
(B) fatigue
(C) plastic deformation
(D) non-plastic deformation.

Q18. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to l00°C will
(A) increase
(B) remain same
(C) first increase and then decrease
(D) show unpredictable behaviour.

Q19. The number of electrons in 1 cm3 of metal would be of the order of
(A) 1010
(B) 1022
(C) 1060
(D) 1062

Q20. 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