Placement Paper

ONGC chemical engineering questions with answers,ONGC previously asked questions for practice,ONGC memory based engineering questions with answers

Chemical Engineering questions with answers
1Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work.

A. isothermal
B. adiabatic
C. isentropic
D. none of these

Answer: Option A

2. Internal energy change of a system over one complete cycle in a cyclic process is

A. zero
B. +ve
C. -ve
D. dependent on the path

Answer: Option A

3. Heating of water under atmospheric pressure is an __________ process.

A. isochoric 
B. isobaric
C. adiabatic 
D. isothermal

Answer: Option B

4 Heating of water under atmospheric pressure is an __________ process.
A. isochoric 
B. isobaric
C. adiabatic 
D. isothermal

Answer: Option B

5 Van Laar equation deals with the activity co-efficients in

A. binary solutions
B. ternary solutions
C. azeotropic mixture only
D. none of these
Answer: Option A

6 Cement Kiln is a

A. rotary Kiln
B. tunnel Kiln
C. natural draft furnace
D. batch furnace
Answer: Option A

7 In a furnace employing forced draught as compared to induced draught,

A. air is sucked in, so air leaks are more and hence the furnace efficiency is reduced.
B. the fan operates hot and hence blades are liable to corrosion and erosion.
C. positive pressure exists in the furnace.
D. none of these
Answer: Option C

8 Regenerators are installed in

A. coke ovens
B. open hearth furnace
C. both (a) & (b)
D. neither (a) nor (b)
Answer: Option C

9 _________ atmosphere is maintained inside an iron blast furnace.

A. Oxidising 
B. Reducing
C. Inert 
D. Decarburising
Answer: Option B

10 Higher efficiency in the combustion of solid fuel can not be achieved by

A. proper fuel preparation.
B. keeping the flue gas exhaust temperature very high.
C. adopting efficient-fuel firing technique & equipment.
D. supplying correct quantity of combustion air.

Answer: Option B
Descrptive questions with answers
1. What is turndown ratio ?
'Turndown ratio' is a flow measurement term that indicates the range a specific flow meter, or meter type, is able to measure...to measure with acceptable accuracy. It is also known as rangeability. It is important when choosing a flow meter technology for a specific application. If a gas flow to be measured is expected to vary between 100,000 m³ per day and 1,000,000 m³ per day, the specific application has a turndown ratio of at 10:1. Therefore the meter requires a turndown ratio of at least 10:1. For example: if the meter had an advertised maximum flow of 2,000,000 m³ per day then the required turndown ratio would be 20:1.
The turndown ratio of each type of meter is limited by theoretical considerations and by practical considerations. For example, orifice meters create a pressure drop in the measured fluid proportional to the square of the velocity. Therefore the range of differential pressure can become too large and compromise accuracy. It can also create process problems such as hydrate formation, and in the case of measuring the discharge of a compressor, there is a limit to how much pressure loss is acceptable.
Turndown ratio is one of a number of considerations in choosing a meter type for an application. Some other considerations are price, maintenance cost, accuracy, the fluid type and the velocity of the flowing fluid.

2. Why Plasticizer is added the paint?
Physical and Chemical Examination of Paints, Varnishes, Lacquers, and ... Test by adding plasticizer to the lacquer solution in an amount equal to the base resin

3. What type of glass is used for the manufacture of Electric bulb?
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light which produces light with a filament wire heated to a high temperature by an electric current passing through it, until it glows (see Incandescence). The hot filament is protected from oxidation with a glass bulb that is filled with inert gas (or evacuated). In a halogen lamp, filament evaporation is prevented by a chemical process that redeposits metal vapor onto the filament, extending its life. The light bulb is supplied with electrical current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.

4. Hydrogenation is carried out in which type of reactor?
Chemical ... Hydrogenation - to treat with hydrogen - is a chemical reaction between ... temperature and/or pressure; 7.3 Flow hydrogenation; 7.4 Industrial reactors ... The reduction reaction is carried out at different temperatures and pressures depending upon the substrate and the activity of the catalyst

5. If O2/ Fuel ratio is increased(or, decreased) how adiabatic flame temperature will vary ?
premixed fuel-air mixture will only burn as long as the fuel concentration is between the ... the flammable range will widen when the initial temperature is increasing. Changes in initial pressure will for hydrocarbons in air not change the LFL .... 
6. Heat loss is maximum when critical radius is 
Heat is lost from the pipe to the surrounding medium at temperature , with a convection heat transfer ... The value of r2 at which heat transfer rate reaches maximum is determined

7. Importance of Biot No. 
A number of important areas were identified: heat transfer ... and Biot numbers on the accuracy of the numerical approximation of the diffusion equation for heat ...

8. Importance of Dirt Factor…
diRtFactor--Late Models by Speed Sports Software (formerly DWR ... If you are missing that "factor" in your life, then you need diRtFactor

9. Why Heavy water is used as moderator in the nuclear reactor ?
Moderator is required in a thermal reactor to slow down the neutrons produced in the fission reaction to .025 ev so that the chain reaction can be 

10. Why D2O is used in nuclear reactor instead of ordinary water?
In comparison, in ordinary water, there are only about 156 deuterium atoms per million hydrogen atoms). .... the biological effects of deuterium per se, but instead on deuterium's ability to .... Heavy water is used in certain types of nuclear reactors where it acts as a .... D2O is more toxic to malignant than normal animal cells .

11. Ordinary water is not preferred in nuclear reactor because
With the discovery of nuclear fission in late 1938, and the need for a neutron ... Partly because of Nazi Germany's over-reliance on heavy water, it did not ... Most modern reactors use enriched uranium and normal "light water" (H2O) moderator. ..... large amounts of power, so the chemical methods are generally preferred.

12. Reverse Osmosis is also called 

(A) Dialysis 
(B) Ultrafiltration
(C) Electrodilysis
(D) Diffusion
Schematics of a reverse osmosis system (desalination) using a pressure exchanger. ..... Prefiltration antiscalants: Scale inhibitors (also known as antiscalants) 

13. The specific surface of spherical particle is defined by….

14. The porosity of a compressible cake is 
(A) Maximum at the filter medium
(B) Maximum at the upstream face
(C) Same throughout the thickness of cake 
(D) Maximum at the filter medium & Minimum at the upstream face.
For a spherical particle of diameter D p, F s =1; for a non-spherical particle, the ... The equivalent diameter is sometimes defined as the diameter of a sphere of ... in each fraction can be calculated and added to give the specific surface

15. Fermentation of alcohol from molasses is followed by which process..
Various factors namely: process design, molasses quality, yeast strain ... interest in ethanol fermentation has been generated over the last two decades ... industry and further addresses the steps followed in trouble shooting.

16. Why Dimensional Analysis is done?
In physics and all science, dimensional analysis is a tool to find or check .... the same is done to the dimensional symbols attached to those quantities

17. Dynamic similarity is
(A) The similarity of shapes
(B) The similarity of streamline pattern
(C) The similarity of forces influencing the fluid motion.
(D) The similarity of discharge.
In physics and all science, dimensional analysis is a tool to find or check .... the same is done to the dimensional symbols attached to those quantities

18. What is control Valve..?
Control valves are valves used to control conditions such as flow, pressure, temperature, and liquid level by fully or partially opening

19. Agitated film evaporators are generally used for….
Thin film or wiped film evaporators are used to separate a mixture of liquids having different ... Generally the vapour outlet is provided on the top side of the shell.

20. In a multiple effect evaporator with forward feed….
There are two feed operations - backward feed and forward feed operations. A brief explanation of these operations: Multi Effect Evaporators. 
21. In a multiple effect evaporator with backward feed….
There are two feed operations - backward feed and forward feed operations. A brief explanation of these operations: Multi Effect Evaporators. 

22. Cost of piping in a fluid processing unit(e.g., distillation) of a chemical process plant is about………….. % of the fixed capital investment?
23. Purchased cost of equipment for a chemical process plant ranges from………….. % of the fixed capital investment?

24. Which of the following methods of depreciation calculation results in minimum book value.

25. In finanacial accounting of a chemical plant, which of the following relationship is valid?


26. Which of the following is not a component of the working capital for a chemical process plant?
(A) Product inventory
(B) In-process inventory
(C) Minimum cash reserve
(D) Storage facilities.

27. Effectiveness factor of a catalyst is given by


28. Which of the following substances is most commonly used for cloud seeding (Artificial Rains)?
(A) Potassium chloride
(B) Silver Iodide
(C) Zinc sulphate
(D) Magnesium hydroxide

29. Why the melting and boiling point of alkali metals are high?


30. Which alkali metal will have large ionic radii in water?
(A) Na
(B) K
(C) Cs
(D) H

31. Which alkali halide have large electro negativity?


32. When alkali metals are exposed to air.


33. How Chilton analogy is related to the friction factor?
34. Why Antioxidants are added to petrol

35. Ammonia synthesis from Natural Gas is done by which process


36. Poison for platinum catalyst is..
(A) Sulphur
(B) Arsenic
(C) Phosphorous
(D) Coke

37. Match the following:
(A) Hydrogenation                 1. Iron
(B) Ammonia synthesis         2. Platinum
                                            3. Zeolite
                                            4. Nickel

38. Match the following:
(A) Catalytic Reforming     1. High speed Diesel
(B) Smoke Point             2. Kerosene
                                        3. Gasoline
                                        4. Aromatics
39. Match the following:
(A) Xtra mile 1. Indian Oil
(B) Power 2. BP
(C) Speed 3. HP

40. The Bode Stability criterion is applicable when: 

(A) Gain and Phase curves decreases continuously with frequency.
(B)Gain curve increases and Phase curves decreases with frequency.
(C)Gain and Phase curves both increses with frequency.
(D)Gain curve decreases and Phase curves increases with frequency.