CHEMICAL ENGINEERING

Question: Diamagnetic materials
[A].

are magnetised by eddy currents only.

[B].

are non-magnetic and can not be magnetised.

[C].

are magnetised in direction opposite to the magnetic field.

[D].

can be magnetised in one direction only.

Answer: Option C

Explanation:

No answer description available for this question.

Question: About __________ ton of coke is required in a cupola to produce one ton of casting.
[A].

0.03

[B].

0.3

[C].

0.8

[D].

1.5

Answer: Option B

Explanation:

No answer description available for this question.

Question: Out of the following __________ iron has the best capability to bear sudden & excessive shocks.
[A].

white

[B].

cast

[C].

wrought

[D].

pig

Answer: Option C

Explanation:

No answer description available for this question.

Question: Lowering of recrystallisation temperature of metals can be achieved by its
[A].

grain refinement.

[B].

purification.

[C].

working at lower temperature.

[D].

all a, b & c.

Answer: Option D

Explanation:

No answer description available for this question.

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.