127. 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
128. The crystal structure of brass is
A.F.C.C.
B.B.C.C.
C.H.C.P.
D.Orthophombic crystalline structure
129. The composition of silver solder is
A.Silver, copper, zinc
B.Silver, tin, nickel
C.Silver, lead, zinc
D.Silver, copper, aluminium
130. Which one of the following metals would work-harden more quickly than the others?
A.Copper
B.Brass
C.Lead
D.Silver
131. 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
132. 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
133. 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
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