561. Bell metal is an alloy of __________________?
A. Copper & zinc
B. Copper & tin
C. Copper & nickel
D. Zinc & tin

562. The specific gravity of coal depends mainly on its ______________ content?
A. Carbon
B. Volatile matter
C. Ash
D. Moisture

563. Which of the following is the main constituent of the mother liquor produced in salt industry ?
A. Quick lime
B. Glauber’s salt
C. Salt petre
D. Bromine

564. Bog iron used for the adsorption of H2S from coke oven gas is___________________?
A. An intimate mixture of saw dust and iron dust (i.e. moist ferric hydroxide)
B. Iron impregnated with resin (usually Bakelite)
C. Carbon free iron
D. None of these

565. To improve the machinability of steel by its softening, it is subjected to __________________?
A. Cold working
B. Annealing
C. Shot blasting
D. Heating

566. With increase in the carbon percentage in the steel, its__________________?
A. Hardness increases
B. Ductility reduces
C. Tensile strength increases
D. All A., B. and C.

567. Bearings subjected to light load are made of________________?
A. White metal
B. Phosphorous bronze
C. Monel
D. Silicon bronze

568. Addition of lead, sulphur and phosphorus to low carbon steel helps in improving its__________________?
A. Corrosion resistance
B. Tensile strength
C. Machinability
D. Compressive strength

569. In SO3 absorber (Contact Process), packing material used is of________________?
A. Cast iron
B. Chemical stoneware
C. Karbate
D. Mild steel

570. __________________ does not contain copper as an alloying element?
A. Nichrome
B. Manganin
C. Perminvar
D. Monel metal

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