531. Nickel as a material of construction__________________?
A. Is used as an alloying element for both ferrous & non-ferrous alloys
B. Is paramagnetic below 415° C (its Curie temperature)
C. Diamagnetic
D. Has a body centred cubic (bcc) crystal lattice structure

532. Lead pipes are not safe for carrying drinking water, because water, containing dissolved oxygen attacks lead thereby forming poisonous Pb(OH)2. Lead pipes are readily corroded by___________________?
A. Dilute HCl
B. Acetic acid
C. Concentrated H2SO4
D. None of these

533. Which one occupies the lowermost position in the electromotive series of metals ?
A. Aluminium
B. Noble metals (Ag, Pt, Au)
C. Zinc
D. Alkali metals (K, Na, Li)

534. ‘Semi steel’ is__________________?
A. Produced by adding 10-20% steel to the cupola charge
B. Stronger than cast iron
C. Both A. and B.
D. Neither A. nor B.

535. How many molecules per unit cell are there in a face centred cubic lattice ?
A. 2
B. 4
C. 6
D. 8

536. Non-ferrous metals and hard steels do not exhibit a definite yield point, when pulled in the testing machine and hence for these cases, a better measure of their elastic properties is defined by the ______________ stress?
A. Ultimate
B. Yield point
C. Proof
D. None of these

537. _______________ is a donor impurity for semi-conductors ?
A. Boron
B. Antimony
C. Gallium
D. None of these

538. Caustic soda is transported in _____________ lined containers ?
A. Glass
B. Nickel
C. Neoprene
D. Either B. or C.

539. When iron is rusted, it is__________________?
A. Converted to a fine powder
B. Reduced
C. Oxidised
D. None of these

540. High speed steel tools retain their hardness upto a temperature of _____________ °C?
A. 500
B. 750
C. 900
D. 1100

NOTE
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