Engineering Materials - Study Mode

[#311] Silicon when added to copper improves
Correct Answer

(C) Hardness and strength

Explanation

Solution: when Silicon is added to copper it improves the hardness and strength

[#312] Nickel when added to copper improves
Correct Answer

(B) Hardness

Explanation

Solution: The addition of nickel to copper improves strength and corrosion resistance while allowing the alloy to remain ductile.

[#313] For the allotropic forms of iron, the points of arrest are
Correct Answer

(D) The points of discontinuity

Explanation

Solution: For the allotropic forms of iron, the points of arrest are The points of discontinuity

[#314] Hematite iron ore contains iron about
Correct Answer

(D) 70%

Explanation

Solution: The principal iron ores are hematite (Fe 2 O 3 ). Hematite is an iron oxide mineral. Hematite contains iron about 70%.

[#315] Thermoplastic materials are those materials which
Correct Answer

(B) Do not become hard with the application of heat and pressure and no chemical change occurs

Explanation

Solution: Thermoplastic materials can be cooled and heated several times without any change in their chemistry or mechanical properties. A thermoplastic, or thermosoftening plastic, is a plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.