169. Age-hardening is related with
A.Stainless steel
B.Gun metal
C.German silver
D.Duralumin

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170. Aluminium bronze contains
A.94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B.92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
C.10% aluminium and 90% copper
D.90% magnesium and 9% aluminium with some copper

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171. Babbit metal is a
A.Lead base alloy
B.Tin base alloy
C.Copper base alloy
D.Both (A) and (C) above

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172. The correct composition of Babbit metal is
A.87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
B.90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
C.87% Sn, 4% Cu, 8% Sb, 1% Al
D.82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg

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173. Duralumin contains
A.94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
B.92.5% aluminium, 40% copper, 2% nickel, and 1.5% Mg
C.10% aluminium and 90% copper
D.90% magnesium and 9% aluminium with some copper

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174. Neutral solution is one which has pH value
A.Greater than 7
B.Less than 7
C.Equal to 7
D.PH value has nothing to do with neutral solution

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175. Acidic solution is one which has pH value
A.Greater than 7
B.Less than 7
C.Equal to 7
D.PH value has nothing to do with neutral solution

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