Addition of lead and bismuth to aluminium results in_________________?

A. Improvement of casting characteristics
B. Improvement of corrosion resistance
C. One of the best known age and precipitation-hardening systems
D. Improving machinability

German silver contains_________________?

A. 1% silver
B. 2.5% silver
C. 5% silver
D. 10% silver

Dow metal contains____________________?

A. 94% aluminium, 4% copper and 0.5% mn, mg, si and fe
B. 92.5% aluminium and, 4% copper, 2% nickel and 1.5% mg
C. 90% aluminium and 90% copper
D. 90% magnesium and 9% aluminium with some copper

Age-hardening is related with______________?

A. Stainless steel
B. Gun metal
C. German silver
D. Duralumin

Babbit metal is a_________________?

A. lead base alloy
B. tin base alloy
C. copper base alloy
D. all of the above

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

The transistor is made of___________________?

A. Silver
B. Gold
C. Copper
D. Germanium

Following elements have face-centred cubic structure__________________?

A. Gamma iron (910° to 1400°c), cu, ag, au, al, ni, pb, pt
B. Mg, zn, ti, zr, br, cd
C. A iron (below 910°c and between 1400 to 1539°c), w
D. All of the above

Pearlite is a combination of___________________?

A. Ferrite and cementite
B. Cementite and gamma iron
C. Ferrite and austenite
D. Ferrite and iron graphite

Lead is poured into the joint between two pipes. These pipes may be made of____________________?

A. Cast iron
B. Vitrified clay
C. Asbestos cement
D. Concrete