Chemical Engineering Basics

Question: Main alloying element in Elinvar used in precision instruments, hair springs for watches etc. is
[A].

chromium

[B].

nickel

[C].

zinc

[D].

aluminium

Answer: Option B

Explanation:

No answer description available for this question.

Question: Addition of silicon to aluminium improves its
[A].

corrosion resistance

[B].

machinability

[C].

castability

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: More than 95% of __________ is present in corrundum.
[A].

SiO2

[B].

A12O3

[C].

CaSiO2

[D].

MgO

Answer: Option B

Explanation:

No answer description available for this question.

Question: Addition of __________ to steel can not impart it high strength at elevated temperature.
[A].

nickel

[B].

magnesium

[C].

silicon

[D].

manganese

Answer: Option B

Explanation:

No answer description available for this question.

Question: Ageing of steel refers to the
[A].

degradation of steel by corrosion.

[B].

failure of steel structure by overstress-ing.

[C].

return of sharp yield point in temper rolled low carbon sheet after a period of time.

[D].

decarburisation of steel by overheating.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Brass parts with high residual tensile stress at the surface are susceptible to season cracking (i.e. spontaneous cracking occuring on exposure to atmospheric corrosion), if its zinc percentage is more than
[A].

5

[B].

10

[C].

20

[D].

35

Answer: Option C

Explanation:

No answer description available for this question.

Question: Alloys having more than 80% copper are generally more
[A].

abrasion resistant.

[B].

corrosion resistant.

[C].

prone to season cracking.

[D].

machinable.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Material having maximum density is
[A].

plutonium

[B].

osmium

[C].

titanium

[D].

uranium

Answer: Option B

Explanation:

No answer description available for this question.

Question: Fibre reinforced plastic (FRP) are
[A].

made of glass fibre and thermoplastic resins.

[B].

anisotropic.

[C].

made of thermosetting resin and glass fibre.

[D].

both ‘b’ & ‘c’

Answer: Option D

Explanation:

No answer description available for this question.

Question: Cast iron contains __________ percent carbon.
[A].

2.5

[B].

3.75

[C].

4.75

[D].

5.25

Answer: Option A

Explanation:

No answer description available for this question.