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
(D) raises its melting point
Which of the following is not the correct method of increasing fatigue limit __________________?
(A) shot peening
(B) nitriding of surface
(C) cold working
(D) surface decarburisation
(D) under-stressing
Which of the following pipes is least corrosion resistant__________________?
(A) brass
(B) mild steel
(C) cast iron
(D) wrought iron
(D) copper
High carbon steel carries carbon %age c_________________?
(A) 0.1 to 0.3%
(B) 0.3 to 0.6%
(C) 0.6 to 0.8%
(D) 0.8 to 1.5%
(D) 1.5 to 2.5%.
The percentage of carbon in low carbon steel is__________________?
(A) 0.05%
(B) 0.15%
(C) 0.3%
(D) 0.5%
(D) 0.7%.
If a refractory contains high content of silicon, it means refractory is__________________?
(A) acidic
(B) basic
(C) neutral
(D) brittle
(D) none of the above
Corrundum contains more than 95% _____________________?
(A) steel
(B) A1203
(C) Si02
(D) MgO
(D) german silver
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
(D) none of the above
Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio_________________?
(A) 50 : 50
(B) 30 : 70
(C) 70 : 30
(D) 40 : 60
(D) 60 : 40
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
(D) 50 : 10 : 20 : 20