Important Alloys and Their Components CDS Questions

CDS Chemistry

Important Alloys and Their Components MCQ Questions


7.
The thin, self-healing protective layer that prevents rusting on the surface of stainless steel is chemically composed mainly of:
A.
Copper oxide
B.
Iron oxide
C.
Zinc oxide
D.
Chromium oxide
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ANSWER :
D. Chromium oxide
8.
Which variant of bronze, containing a small percentage of phosphorus to improve its strength and wear resistance, is used for springs and electrical contacts?
A.
Bell metal
B.
Phosphor bronze
C.
Gun metal
D.
Aluminium bronze
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ANSWER :
B. Phosphor bronze
9.
Which variant of bronze, containing aluminium instead of tin as the main alloying element with copper, is known for its high strength and used in marine hardware?
A.
Gun metal
B.
Aluminium bronze
C.
Bell metal
D.
Phosphor bronze
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ANSWER :
B. Aluminium bronze
10.
Increasing the proportion of zinc within the typical range used in brass generally tends to:
A.
Turn the alloy into pure bronze
B.
Increase its hardness and strength, though excessive zinc reduces ductility
C.
Decrease its overall hardness and strength
D.
Have absolutely no effect on its mechanical properties
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ANSWER :
B. Increase its hardness and strength, though excessive zinc reduces ductility
11.
Why has bronze traditionally been preferred over pure copper for casting bells and statues?
A.
Bronze is cheaper to produce than pure copper in every era
B.
Bronze is magnetic while copper is not
C.
Pure copper cannot be melted at all
D.
Bronze is harder, more corrosion-resistant, and gives better sound resonance than pure copper
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ANSWER :
D. Bronze is harder, more corrosion-resistant, and gives better sound resonance than pure copper
12.
Stainless steel grades that additionally contain molybdenum, along with chromium and nickel, are specifically valued for their enhanced resistance to:
A.
Thermal expansion
B.
Electrical conductivity
C.
Magnetism
D.
Pitting and corrosion in chloride-rich (e.g., marine) environments
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ANSWER :
D. Pitting and corrosion in chloride-rich (e.g., marine) environments