1000+ Engineering Materials MCQ for DRDO [Solved]

1. An engineer's hammer is made of
A. Cast iron
B. Forged steel
C. Mild steel
D. High carbon steel
Answer : D

2. The machinability of aluminium increases when __________ is added to aluminium.
A. Copper
B. Magnesium
C. Silicon
D. Lead and bismuth
Answer : D

3. Amorphous material is one
A. In which atoms align themselves in a geometric pattern upon solidification
B. In which there is no definite atomic structure and atoms exist in a random pattern just as in a liquid
C. Which is not attacked by phosphorous
D. Which emits fumes on melting
Answer : B

4. The percentage carbon content in wrought iron is about
A. 0.02
B. 0.1
C. 02
D. 0.4
Answer : A

5. Super conduction by metals is observed in the temperature range of
A. Below 10°K
B. Above 100°K
C. Around 0°C
D. Around 100°C
Answer : A

6. Which of the following impurity in cast iron makes it hard and brittle?
A. Silicon
B. Sulphur
C. Manganese
D. Phosphorus
Answer : B

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

8. Delta metal is an alloy of
A. Copper, zinc and iron
B. Iron, nickel and copper
C. Iron, lead and tin
D. Iron, aluminium and magnesium
Answer : A

9. Steel made from phosphate iron is
A. Brittle
B. Hard
C. Ductile
D. Tough
Answer : A

10. The aluminium alloy, mainly used, for anodized utensil manufacture, is
A. Duralumin
B. Y-alloy
C. Magnalium
D. Hindalium
Answer : D

11. 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

12. Free cutting steels
A. Contain carbon in free from
B. Require minimum cutting force
C. Is used where rapid machining is the prime requirement
D. Can be cut freely
Answer : C

13. In a hardening process, 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 : B

14. Which of the following statement is correct?
A. The product produced by blast-furnace is called cast iron
B. The pig iron is the name given to the product produced by cupola
C. The cast iron has high tensile strength
D. The chilled cast iron has no graphite
Answer : D

15. Which of the following represents the allotropic forms of iron?
A. Alpha iron, beta iron and gamma iron
B. Alpha iron and beta iron
C. Body centred cubic iron and face centred cubic iron
D. Alpha iron, gamma from and delta iron
Answer : D

16. Hardness of lower bainite (tempered martensite) is about
A. RC 65
B. RC 48
C. RC 57
D. RC 80
Answer : C

17. An important property of high silicon (12-18%) cast iron is the high
A. Hardness
B. Brittleness
C. Plasticity
D. Ductility
Answer : A

18. Pearlite consists 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 : B

19. 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
Answer : B

20. Drop forging dies contain carbon of the order of
A. 0.1 to 0.2 %
B. 0.25 to 0.5 %
C. 0.6 to 0.7 %
D. 0.7 to 0.9 %
Answer : C

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

22. The lower critical point for all steels is
A. 600°C
B. 700°C
C. 723°C
D. 913°C
Answer : C

23. 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
Answer : C

24. German silver contains
A. 1% silver
B. 2% silver
C. 5% silver
D. No silver
Answer : D

25. When filing or machining cast iron makes our hands black, then it shows that ________ is present in cast iron.
A. Cementite
B. Free graphite
C. Both A and B
D. None of these
Answer : B

26. The machinability of steel is improved by adding
A. Nickel
B. Chromium
C. Nickel and chromium
D. Sulphur, lead and phosphorus
Answer : D

27. According to Indian standard specifications, plain carbon steel designated by 40 C8 means that the carbon content is
A. 0.04 %
B. 0.35 to 0.45 %
C. 0.4 to 0.6 %
D. 0.6 to 0.8 %
Answer : B

28. Age hardening is related to
A. Duralumin
B. Brass
C. Copper
D. Silver
Answer : A

29. Closed packed hexagonal space lattice is found in
A. Zinc, magnesium, cobalt, cadmium, antimony and bismuth
B. Gamma-iron, aluminium, copper, lead, silver and nickel
C. Alpha-iron, tungsten, chromium and molybdenum
D. None of the above
Answer : A

30. Large forgings, crank shafts, axles normally contain carbon up to
A. 0.05 to 0.20 %
B. 0.20 to 0.45 %
C. 0.45 to 0.55 %
D. 0.55 to 1.0 %
Answer : C

31. The hardness of steel increases if it contains
A. Pearlite
B. Ferrite
C. Cementite
D. Martensite
Answer : C

32. Eutectoid steel consists of
A. Wholly pearlite
B. Wholly austenite
C. Pearlite and ferrite
D. Pearlite and cementite
Answer : A

33. 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
Answer : B

34. 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
Answer : C

35. In high speed steels, manganese is used to tougher the metal and to increase its
A. Yield point
B. Critical temperature
C. Melting point
D. Hardness
Answer : B

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

37. The alloying element which can replace tungsten in high speed steels is
A. Nickel
B. Vanadium
C. Cobalt
D. Molybdenum
Answer : D

38. The main alloying elements high speed steel in order of increasing proportion are
A. Vanadium, chromium, tungsten
B. Tungsten, titanium, vanadium
C. Chromium, titanium, vanadium
D. Tungsten, chromium, titanium
Answer : A

39. 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

40. Iron is
A. Paramagnetic
B. Ferromagnetic
C. Ferroelectric
D. Dielectric
Answer : B

41. A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as
A. Allotropic change
B. Recrystallisation
C. Heat treatment
D. Precipitation
Answer : A

42. Combined carbon in iron makes the metal
A. Soft and gives coarse grained crystalline structure
B. Soft and gives a fine grained crystalline structure
C. Hard and gives a coarse grained crystalline structure
D. Hard and gives a fine grained crystalline structure
Answer : D

43. The temperature required for full annealing in hypereutectoid steel is
A. 30°C to 50°C above upper critical temperature
B. 30°C to 50°C below upper critical temperature
C. 30°C to 50°C above lower critical temperature
D. 30°C to 50°C below lower critical temperature
Answer : C

44. 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 :