Engineering Materials 21

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Objective Questions and Answer: Engineering Materials 21

Subject: Engineering Materials 21

Part 21: Objective questions and answers of Engineering Materials

 

Q1. Steel made from phosphatic iron is

a) Brittle

b) Hard

c) Ductile

d) Tough

 

Q2. Ductile 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

 

Q3. Brass 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

 

Q4. The crystal structure of brass is

a) F.C.C.

b) B.C.C.

c) H.C.P.

d) Orthorhombic crystalline structure

 

Q5. The composition of silver solder is

a) Silver, copper, zinc

b) Silver, tin, nickel

c) Silver, lead, zinc

d) Silver, copper, aluminium

 

Q6. Which one of the following metals would work-harden more quickly than the others?

a) Copper

b) Brass

c) Lead

d) Silver

 

Q7. A specimen of aluminium metal when observed under microscope shows

a) B.C.C. crystalline structure

b) F.C.C. crystal structure

c) H.C.P. structure

d) A complex cubic structure

 

Q8. 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

 

Q9. Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio

a) 50:50:00

b) 30 : 70

c) 70:30:00

d) 40 : 60

 

Q10. Corrosion resistance of steel is increased by adding

a) Chromium and nickel

b) Nickel and molybdenum

c) Aluminium and zinc

d) Tungsten and sulfur

 

Q11. Corrundum contains more than 95%

a) Steel

b) A1203

c) Si02

d) Mgo

 

Q12. Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio

a) 50 : 20 : 20 : 10

b) 40 : 30 : 20 : 10

c) 50 : 20 : 10 : 20

d) 30 : 20 : 30 : 20

 

Q13. If a refractory contains high content of silicon, it means refractory is

a) Acidic

b) Basic

c) Neutral

d) Brittle

 

Q14. Bell metal 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

 

Q15. Which of the following is used for bearing liner

a) Gun metal

b) Bronze

c) Bell metal

d) Babbit metal

 

Q16. 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

 

Q17. Structural steel contains following principal alloying elements

a) Nickel, chromium and manganese

b) Tungsten, molybdenum and phosphorous

c) Lead, tin, aluminium

d) Zinc, sulphur, and chromium

 

Q18. Aluminium bronze contains aluminium and copper in the ratio of

a) 50:50:00

b) 40 : 60

c) 60:40:00

d) 0.479166667

 

Q19. 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

 

Q20. Muntz metal contains copper and zinc in the ratio of

a) 50:50:00

b) 40 : 60

c) 60:40:00

d) 0.888888889

 

Part 21: Objective questions and answers of Engineering Materials

 

Q1. Answer a

Q2. Answer d

Q3. Answer a

Q4. Answer a

Q5. Answer a

Q6. Answer b

Q7. Answer b

Q8. Answer a

Q9. Answer b

Q10. Answer a

Q11. Answer b

Q12. Answer a

Q13. Answer c

Q14. Answer d

Q15. Answer d

Q16. Answer a

Q17. Answer a

Q18. Answer d

Q19. Answer b

Q20. Answer

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