NEET - Engineering Materials 1000+ MCQ [Solved] PDF Download

1. The most effective inhibitor of grain growth, when added in small quantities is
A. Carbon
B. Vanadium
C. Manganese
D. Cobalt
Answer : B

2. A cold chisel is made of
A. Mild steel
B. Cast iron
C. HSS
D. High carbon
Answer : D

3. Austenite is a combination of
A. Ferrite and cementite
B. Cementite and gamma iron
C. Ferrite and austenite
D. Ferrite and iron graphite
Answer : B

4. German silver is an alloy of
A. Silver and some impurities
B. Refined silver
C. Nickel, Copper and zinc
D. Nickel and copper
Answer : C

5. A reversible change in the atomic structure of steel with corresponding change in the properties is known as
A. Molecular change
B. Physical change
C. Allotropic change
D. Solidus change
Answer : C

6. Vanadium in high speed steels
A. Promotes decarburisation
B. Provides high hot hardness
C. Forms very hard carbides and thus increases wear resistance
D. Promotes retention of austenite
Answer : C

7. The coordination number of a face centred cubic space lattice is
A. Six
B. Twelve
C. Eighteen
D. Twenty
Answer : B

8. 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
Answer : B

9. The blade of a power saw is made of
A. Boron steel
B. High speed steel
C. Stainless steel
D. Malleable cast iron
Answer : B

10. Which of the following impurity in cast iron promotes graphite nodule formation and increases the fluidity of the molten metal?
A. Silicon
B. Sulphur
C. Manganese
D. Phosphorus
Answer : A

11. In induction hardening ________ is high.
A. Current
B. Voltage
C. Frequency
D. Temperature
Answer : C

12. White cast iron
A. Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
B. Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
C. Is produced by annealing process. It is soft, tough and easily machined metal
D. Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
Answer : B

13. The silicon steel is widely used for
A. Connecting rods
B. Cutting tools
C. Generators and transformers in the form of laminated cores
D. Motor car crankshafts
Answer : C

14. A steel containing 16 to 18% chromium and about 0.12% carbon is called
A. Ferritic stainless steel
B. Austenitic stainless steel
C. Martenistic stainless steel
D. Nickel steel
Answer : A

15. Pick up the wrong statement
A. Aluminium in steel results in excessive grain growth
B. Manganese in steel induces hardness
C. Nickel and chromium in steel helps in raising the elastic limit and improve the resilience and ductility
D. Tungsten in steels improves magnetic properties and hardenability
Answer : A

16. The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
A. Chromium
B. Nickel
C. Vanadium
D. Cobalt
Answer : D

17. The usual composition of a soldering alloy is
A. Tin, lead and small percentage of antimony
B. Tin and lead
C. Tin, lead and silver
D. Tin and copper
Answer : A

18. The unique property of cast iron is its high
A. Malleability
B. Ductility
C. Surface finish
D. Damping characteristics
Answer : D

19. The portion of the blast furnace below its widest cross-section is called
A. Hearth
B. Stack
C. Bosh
D. Throat
Answer : C

20. Cementite consist of
A. 13% carbon and 87% ferrite
B. 13% cementite and 87% ferrite
C. 13% ferrite and 87% cementite
D. 6.67% carbon and 93.33% iron
Answer : D

21. Addition of silicon to aluminium results in
A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation hardening systems
D. Improving machinability
Answer : A

22. Addition of lead and bismuth to aluminium results in
A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation hardening systems
D. Improving machinability
Answer : D

23. Phosphor bronze contains
A. 0.5% of phosphorous
B. 1% phosphorous
C. 2.5% phosphorous
D. None of the above
Answer : D

24. Stress relaxation is the phenomenon
A. In which parts are not loaded
B. In which stress remains constant on increasing load
C. In which deformation tends to loosen the joint and produces a stress reduced
D. Stress reduces on increasing load
Answer : C

25. Which of the following has a fine gold colour and is used for imitation jewellery?
A. Silicon bronze
B. Aluminium bronze
C. Gun metal
D. Babbitt metal
Answer : B

26. Which of the following element results in presence of free graphite in C.I.?
A. Carbon
B. Sulphur
C. Silicon
D. Manganese
Answer : C

27. Bell metal contains
A. 70% copper and 30% zinc
B. 90% copper and 10% ti
C. 85 - 92% copper and rest tin with little lead and nickel
D. 70 - 75% copper and rest tin
Answer : D

28. The metal suitable for bearings subjected to light loads, is
A. Silicon bronze
B. White metal
C. Monel metal
D. Phosphor bronze
Answer : D

29. The percentage of carbon in low carbon steel is
A. 0.05 %
B. 0.15 %
C. 0.3 %
D. 0.5 %
Answer : B

30. Depth of hardness of steel is increased by addition of
A. Nickel
B. Chromium
C. Tungsten
D. Vanadium
Answer : B

31. Manganese is added in low carbon steel to
A. Make the steel tougher and harder
B. Raise the yield point
C. Make the steel ductile and of good bending qualities
D. All of the above
Answer : C

32. Perminvar alloy having constant permeability is an alloy of
A. Nickel, copper and iron
B. Nickel, copper and zinc
C. Copper, nickel and antimony
D. Iron, zinc and bismuth
Answer : A

33. When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces
A. White cast iron
B. Nodular cast iron
C. Malleable cast iron
D. Alloy cast iron
Answer : D

34. Which of the following statement is incorrect about duralumin?
A. It is prone to age hardening
B. It can be forged
C. It has good machining properties
D. It is lighter than pure aluminium
Answer : D

35. The carbon in the pig iron varies from
A. 0.1 to 0.5 %
B. 0.5 to 1 %
C. 1 to 5 %
D. 5 to 10 %
Answer : C

36. Carbon in iron is an example of
A. Substitutional solution
B. Interstitial solid solution
C. Intermetallic compounds
D. All of the above
Answer : B

37. The hardness of steel primarily depends on
A. Percentage of carbon
B. Percentage of alloying elements
C. Heat treatment employed
D. Shape of carbides and their distribution in iron
Answer : D

38. In basic Bessemer process, the furnace is lined with
A. Silica bricks
B. A mixture of tar and burnt dolomite bricks
C. Both (A) and (B)
D. None of these
Answer : B

39. In process annealing, the hypo eutectoid steel is
A. Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
B. Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
C. Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
D. Heated below or closes to the lower critical temperature and then cooled slowly
Answer : D

40. 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
Answer : A

41. Duralumin contains
A. 94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B. 92.5% aluminium, 40% copper, 2% nickel, and 1.5% Mg
C. 10% aluminium and 90% copper
D. 90% magnesium and 9% aluminium with some copper
Answer : A

42. A small percentage of boron is added to steel in order to
A. Increase hardenability
B. Reduce machinability
C. Increase wear resistance
D. Increase endurance strength
Answer : A

43. Which one of the following metals would work-harden more quickly than the others?
A. Copper
B. Brass
C. Lead
D. Silver
Answer : B

44. 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
Answer : A

45. Which of the following constituents of steels is softest and least strong?
A. Austenite
B. Pearlite
C. Ferrite
D. Cementite
Answer : C

46. The correct sequence for descending order of machinability is
A. Grey cast iron, low carbon steel, wrought iron
B. Low carbon steel, grey cast iron, wrought iron
C. Wrought iron, low carbon steel, grey cast iron
D. Wrought iron, grey cast iron, low carbon steel
Answer : A

47. Cupola produces following material
A. Cast iron
B. Pig iron
C. Wrought iron
D. Malleable iron
Answer : A

48. White cast iron contains carbon in the form of
A. Free carbon
B. Graphite
C. Cementite
D. White carbon
Answer : C

49. The ability of a material to resist softening at high temperature is known as
A. Creep
B. Hot tempering
C. Hot hardness
D. Fatigue
Answer : C

50. Grey cast iron
A. Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
B. Is also known as chilled cast iron is obtained by cooling rapidly. It is almost unmachinable
C. Is produced by annealing process. I is soft, tough and easily machined metal
D. Is produced by small additions o magnesium (or cerium) in the ladle Graphite is in nodular or spheroidal form and is well dispersed throughout the material
Answer : A