Chemical Engineering Basics MCQs

Question 1

Current employed in resistance welding ranges from __________ kVA/cm 2 .

Accepted Answer

4.5 to 6.2

Answer

1.2 to 2.5

Answer

7.5 to 8.5

Answer

10.5 to 15.5

Question 2

Unbreakable crockeries are made from __________ polymers.

Accepted Answer

Polyurathane

Answer

Polystyrene

Answer

Melamine

Answer

Polystyrene

Question 3

For the irreversible reaction, C a + 2C = C a C 2 , ΔH°298 = -60000 J.mole -1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be

Accepted Answer

90000 J

Answer

30000 J

Answer

60000 J

Answer

240000 J

Question 4

Basicity [%Cao + %MgO/% SiO 2 ) of the slag in Indian blast furnace is in the range of

Accepted Answer

1.1 - 1.4

Answer

0.7 - 1.0

Answer

1.5 - 1.8

Answer

2.0 - 2.5

Question 5

Boiler rating is normally done in terms of

Accepted Answer

Steam output (tons/hr)

Answer

Steam temperature & pressure

Answer

Heat transfer rate (kcal/hr)

Answer

Heat transfer area (m 2 )

Question 6

Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as

Accepted Answer

Gr 0.25 , Gr

Answer

Gr 0.25 , Gr 0.33

Answer

Gr, Gr 0.25

Answer

Gr 0.33 , Gr 0.25

Question 7

The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to (where, T = absolute temperature, °K) T

Accepted Answer

$$\frac{1}{{	ext{T}}}$$

Answer

T 2

Answer

$$\frac{1}{{{{	ext{T}}^2}}}$$

Question 8

The unit of g c is

Accepted Answer

lb m /lb f . ft/seC₂

Answer

lb f /lb m . ft/seC₂

Answer

lb m /lb f . seC₂/ft

Answer

lb f /lb m . seC₂/ft

Question 9

Heat flow across a hollow sphere of inner radius 'r 1 ' and outer radius 'r 2 ' is directly proportional to

Accepted Answer

$$\frac{{{{	ext{r}}_2}\,.\,{{	ext{r}}_1}}}{{{{	ext{r}}_2} - {{	ext{r}}_1}}}$$

Answer

$$\frac{{{{	ext{r}}_2} - {{	ext{r}}_1}}}{{{{	ext{r}}_1} - {{	ext{r}}_2}}}$$

Answer

$$\frac{{{{	ext{r}}_1} + {{	ext{r}}_2}}}{{{{	ext{r}}_1}\,.\,{{	ext{r}}_2}}}$$

Answer

$$\frac{{{{	ext{r}}_1}\,.\,{{	ext{r}}_2}}}{{{{	ext{r}}_1} + {{	ext{r}}_2}}}$$