Chemical Engineering Basics MCQs

Question 1

The thickness of oxide film is y at time t. If K 1 , K 2 and K 3 are the temperature dependent constants, the parabolic law of oxidation is given by

Accepted Answer

y 2 = 2K 1 t + K 2

Answer

y = K 1 ln (K 2 t + K 3 )

Answer

y = K 1 t + K 2

Answer

y = K 1 t 3 + K 2

Question 2

Limestone addition in the blast furnace is done to flux __________ present in the raw materials.

Accepted Answer

SiO 2

Answer

Al 2 O 3

Answer

MnO 2

Answer

P

Question 3

The approximate height of a blast furnace having a useful volume of 2000 m 3 is about __________ metres

Accepted Answer

55

Answer

25

Answer

35

Answer

75

Question 4

Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m.k) of 15 mm diameter exposed to air (h = 20W/m 2 .k), when the insulation thickness is __________ mm.

Accepted Answer

25

Answer

15

Answer

10

Answer

30

Question 5

Which of the following is an acidic constituent of B.F. slag?

Accepted Answer

SiO 2

Answer

FeO

Answer

MgO

Answer

CaO

Question 6

The main constituent of bones is

Accepted Answer

Ca 3 (PO 4 ) 2

Answer

CaF 2

Answer

CaCO 3

Answer

CaCl 2

Question 7

Theoretical volume of oxygen required for complete combustion of 1 Nm 3 of acetylene, in oxy-acetylene welding is __________ Nm 3 .

Accepted Answer

2.5

Answer

0.5

Answer

1

Answer

2

Question 8

Maraging steels derive their strength from the following mechanism:

Accepted Answer

A fine, highly dislocated and strong martensite

Answer

Fine dispersions of intermetallics of Fe, Ni, Ti etc

Answer

Fine dispersions of alloy carbides in a ferrite matrix

Answer

Fine dispersions of Fe 3 C nucleated on dislocations in austenite

Question 9

Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as

Accepted Answer

Re -0.8 , Re 0.5

Answer

Re 0.8 , Re -0.5

Answer

Re 0.8 , Re 0.5