1000+ Engineering Materials MCQ for ISRO Recruitment [Solved]

1. Duralumin contains
A. 3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
B. 3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
C. 4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
D. 5 to 6% tin, 2 to 3% copper and rest aluminium
Answer : A

2. The material in which the atoms are arranged chaotically, is called
A. Amorphous material
B. Mesomorphous material
C. Crystalline material
D. None of these
Answer : A

3. Tungsten when added to steel ________ the critical temperature.
A. Does not effect
B. Lowers
C. Raises
D. None of these
Answer : C

4. Age-hardening is related with
A. Stainless steel
B. Gun metal
C. German silver
D. Duralumin
Answer : D

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

6. Monel metal is an alloy of
A. Nickel and copper
B. Nickel and chromium
C. Nickel, Chromium and iron
D. Copper and chromium
Answer : A

7. The crystal of alpha iron is
A. Body centered cubic
B. Face centered cubic
C. Hexagonal close packed
D. Cubic structure
Answer : A

8. In spheroidising process, the steel is
A. Heated below the lower critical temperature and then cooled slowly
B. Heated up to the lower critical temperature and then cooled in still air
C. Heated slightly above the lower critical temperature and then cooled slowly to a temperature of 600°C
D. None of the above
Answer : C

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

10. The material widely used for making pendulums of clocks is
A. Stainless steel
B. High speed steel
C. Heat resisting steel
D. Nickel steel
Answer : D

11. 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

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

13. 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

14. Cartridge brass can be
A. Cold rolled into sheets
B. Drawn into wires
C. Formed into tube
D. Any one of these
Answer : D

15. The charge of the blast furnace consists of
A. Calcined ore (8 parts), coke (4 parts) and limestone (1 part)
B. Calcined ore (4 parts), coke (1 part) and limestone (8 parts)
C. Calcined ore (1 part), coke (8 parts) and limestone (4 parts)
D. Calcined ore, coke and limestone all in equal parts
Answer : A

16. Addition of manganese 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 : B

17. The presence of hydrogen in steel causes
A. Reduced neutron absorption cross-section
B. Improved Weldability
C. Embrittlement
D. Corrosion resistance
Answer : C

18. The strength is the ability of a material to resist
A. Deformation under stress
B. Externally applied forces with breakdown or yielding
C. Fracture due to high impact loads
D. None of these
Answer : B

19. Which is false statement about normalizing? Normalizing is done to
A. Refine grain structure
B. Reduce segregation in casting
C. Improve mechanical properties
D. Induce stresses
Answer : D

20. Cast iron is characterised by minimum of following percentage of carbon
A. 0.2 %
B. 0.8 %
C. 1.3 %
D. 2 %
Answer : D

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

22. 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

23. 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

24. Delta-iron occurs between the temperature ranges of
A. 400°C to 600°C
B. 600°C to 900°C
C. 900°C to 1400°C
D. 1400°C to 1530°C
Answer : D

25. 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

26. Heavy duty leaf and coil springs contain carbon of the following order
A. 0.2 %
B. 0.5 %
C. 0.8 %
D. 1.0 %
Answer : D

27. 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

28. The hardness of steel depends upon the
A. Amount of cementite it contains
B. Amount of carbon it contains
C. Contents of alloying elements
D. Method of manufacture of steel
Answer : A

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

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

31. The stiffness is the ability of a material to resist
A. Deformation under stress
B. Fracture due to high impact loads
C. Externally applied forces with breakdown or yielding
D. None of the above
Answer : A

32. Iron-carbon alloys containing 1.7 to 4.3% carbon are known as
A. Eutectic cast irons
B. Hypoeutectic cast irons
C. Hypereutectic cast irons
D. None of these
Answer : B

33. An alloy of copper, tin and zinc is known as
A. Brass
B. Bronze
C. Gun metal
D. Muntz metal
Answer : C

34. Which of the following pipes is least corrosion resistant?
A. Brass
B. Mild steel
C. Cast iron
D. Wrought iron
Answer : D

35. Which is false statement about properties of aluminium?
A. Modulus of elasticity is fairly low
B. Wear resistance is very good
C. Fatigue strength is not high
D. Creep strength limits its use to fairly low temperatures
Answer : B

36. When medium carbon steel is heated to coarsening temperature
A. There is no change in grain size
B. The average grain size is a minimum
C. The grain size increases very rapidly
D. The grain size first increases and then decreases very rapidly
Answer : C

37. 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

38. 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

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

40. Maximum percentage of carbon in austenite is
A. 0.025 %
B. 0.26 %
C. 0.8 %
D. 1.7 %
Answer : D

41. The coke in the charge of blast furnace
A. Controls the grade of pig iron
B. Acts as an iron bearing mineral
C. Supplies heat to reduce ore and melt the iron
D. Forms a slag by combining with impurities
Answer : C

42. The basic constituents of Hastelloy are
A. Aluminium, copper etc.
B. Nickel, molybdenum etc.
C. Nickel, Copper, etc.
D. All of the above
Answer : B

43. A material is said to be allotropic, if it has
A. Fixed structure at all temperatures
B. Atoms distributed in random pattern
C. Different crystal structures at different temperatures
D. Any one of the above
Answer : C

44. Pick up the wrong statement Nickel and chromium in steel help in
A. Providing corrosion resistance
B. Improving machining properties
C. Providing high strength at elevated temperatures
D. Raising the elastic limit
Answer : B

45. Shock resistance of steel is increased by adding
A. Nickel
B. Chromium
C. Nickel and chromium
D. Sulphur, lead and phosphorus
Answer : C

46. Sulphur in pig iron tends to make it
A. Hard
B. Soft
C. Ductile
D. Tough
Answer : A

47. Machining properties of steel are improved by adding
A. Sulphur, lead, phosphorous
B. Silicon, aluminium, titanium
C. Vanadium, aluminium
D. Chromium, nickel
Answer : A

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

49. 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

50. The elastic stress strain behaviour of rubber is
A. Linear
B. Nonlinear
C. Plastic
D. No fixed relationship
Answer : B