Engineering Materials objective questions with answers part6

Q1. Malleable cast iron
(A) contains l.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) All of these

Q2. Preheating is essential in welding
(A) cast iron
(B) high speed steel
(C) all non-ferrous materials
(D) all of the above

Q3. The hardness of steel primarily depends on
(A) percentage of carbon
(B) percentage of alloying elements
(C) method of manufacture
(D) shape of carbides and their distribution in iron.

Q4. Steel made from phosphatic iron is
(A) brittle
(B) hard
(C) ductile
(D) tough

Q5. 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

Q6. Brass contains
(A) 70% copper and 30% zinc
(B) 90% copper and 10% tin
(C) 85-95% copper and rest tin with little lead and nickel
(D) 70% copper and 30% tin.

Q7. The crystal structure of brass is
(A) F.C.C.
(B) B.C.C.
(C) H.C.P.
(D) Orthorhombic crystalline structure

Q8. The composition of silver solder is
(A) silver, copper, zinc
(B) silver, tin, nickel
(C) silver, lead, zinc
(D) silver, copper, aluminium

Q9. Which one of the following metals would work-harden more quickly than the others?
(A) copper
(B) brass
(C) lead
(D) aluminium.

Q10. 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) orthorhombic crystalline structure.

Q11. 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

Q12. Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio
(A) 50:50:00
(B) 31:10:00
(C) 80:20:00
(D) 41:00:00

Q13. Corrosion resistance of steel is increased by adding
(A) chromium and nickel
(B) nickel and molybdenum
(C) aluminium and zinc
(D) tungsten and sulfur

Q14. Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio
(A) 50 : 20 : 20 : 10
(B) 50 : 30 : 10 : 10
(C) 50 : 20 : 10 : 20
(D) 30 : 20 : 30 : 20

Q15. If a refractory contains high content of silicon, it means refractory is
(A) acidic
(B) basic
(C) neutral
(D) brittle

Q16. Bell metal contains
(A) 70% copper and 30% zinc
(B) 90% copper and 10% tin
(C) 85-92% copper and rest tin with lead and nickel
(D) 70-75% copper and rest tin

Q17. Which of the following is used for bearing liner
(A) gun metal
(B) bronze
(C) bell metal
(D) babbit metal

Q18. 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, grey cast iron, low carbon steel
(D) grey cast iron, wrought iron, low carbon steel.

Q19. 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

Q20. Aluminium bronze contains aluminium and copper in the ratio of
(A) 50:50:00
(B) 41:00:00
(C) 60:40:00
(D) 11:30:00