mechanical engineering MCQs – Page 134

Practise multiple-choice questions from mechanical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

mechanical engineering Mcqs

1. compressors gas turbines and jet engines 2. theory of machines 3. nuclear power plants 4. engineering materials 5. strength of materials mechanical engineering 6. thermodynamics 7. heat transfer 8. i c engines 9. steam boilers engines nozzles and turbines 10. engineering mechanics 11. fluid mechanics mechanical engineering 12. production technology 13. machine design 14. hydraulic machines 15. workshop technology 16. refrigeration and air conditioning

2661. The metallic structure of mild steel is_________________?
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A. orthorhombic crystal

B. face centred cubic

C. body centred cubic

D. hexagonal close packed

E. cubic structure

2662. Maximum percentage of carbon in ferrite is___________________?
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A. 0.25%

B. 0.06%

C. 0.10%

D. 0.8%.

E. 0.025%

2663. Hardness of lower bainite (tempered martensite) is about________________?
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A. RC 57

B. RC 48

C. RC 32

D. RC 65

E. RC 80

2664. Annealing of white cast iron results in production of_________________?
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A. grey iron

B. spheroidal iron

C. none of the above

D. nodular iron

E. malleable iron

2665. Which of the following elements does not impart hardness to steel__________________?
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A. copper

B. chromium

C. silicon

D. none of the above

E. nickel

2666. Heavy duty leaf and coil spring* contain carbon of the following order ________________?
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A. 1.0%

B. 0.50%

C. 1.5%.

D. 0.20%

E. 0.80%

2667. Which of the following has highest specific strength of all structural materials__________________?
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A. chromium alloys

B. none of the above

C. titanium alloys

D. magnesium alloys

E. magnetic steel alloys

2668. An engineers hammer is made of___________________?
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A. forged steel

B. high carbon steel

C. cast iron

D. mild steel

E. H.S.S

2669. Pearlite is a combination of___________________?
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A. ferrite and cementite

B. cementite and gamma iron

C. pearlite and ferrite

D. ferrite and iron graphite

E. ferrite and austenite

2670. Malleable cast iron _________________?
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A. contains l.7 to 3.5% carbon in free state and is obtained by the slow cooling of molten cast iron

B. none of the above

C. is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable

D. is produced by small additions of magnesium (or cerium) in the ladle. Graphite is in the nodular or spheroidal form and is well dispersed throughout the material

E. is produced by annealing process. It is soft, tough, and easily machined metal

2671. In mottled cast iron, carbon is available in__________________?
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A. nodular form

B. flat form

C. combined form

D. free form

E. partly in free and partly in combined state

2672. Weld decay is the phenomenon found with _________________?
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A. wrought iron

B. non-ferrous materials

C. mild steel

D. cast iron