MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 299 Mcqs, each offering curated multiple-choice questions to sharpen your RRB Junior Engineer knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
TLV of lead for public sewer/waste water is about __________ ppm. |
| A. | 1 |
| B. | 25 |
| C. | 150 |
| D. | 650 |
| Answer» B. 25 | |
| 2. |
Which of the following is the most active zone of atmosphere in which weathering events like rain, storm & lightning occur ? |
| A. | Thermosphere |
| B. | Troposphere |
| C. | Stratosphere |
| D. | none of these |
| Answer» C. Stratosphere | |
| 3. |
Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causes |
| A. | fire hazards. |
| B. | explosion hazards. |
| C. | persistent foam. |
| D. | depletion of dissolved oxygen. |
| Answer» D. depletion of dissolved oxygen. | |
| 4. |
Color test of water is done with an instrument called |
| A. | tintometer |
| B. | colorimeter |
| C. | electro-chemical cell |
| D. | turbidimeter |
| Answer» B. colorimeter | |
| 5. |
Presence of bacteria in potable (drinking) water causes |
| A. | turbidity |
| B. | disease |
| C. | bad odour |
| D. | bad taste & colour |
| Answer» C. bad odour | |
| 6. |
The effect of increase in carbon dioxide level of the atmosphere and its profound effect on our climate is called the |
| A. | catalytic conversion |
| B. | green house effect |
| C. | global warming |
| D. | both (b) and (c) |
| Answer» E. | |
| 7. |
The resistance of water to the passage of light through it is a measure of the |
| A. | turbidity |
| B. | color |
| C. | hardness |
| D. | dissolved gases |
| Answer» B. color | |
| 8. |
Which of the following is the most major constituents of air pollutants ? |
| A. | Oxides of sulphur |
| B. | Oxides of nitrogen |
| C. | Carbon monoxide |
| D. | Hydrogen sulphide |
| Answer» B. Oxides of nitrogen | |
| 9. |
The amount of chemical coagulant added for treatment of polluted water __________ with increase in temperature of the polluted water to be treated. |
| A. | decreases. |
| B. | increases. |
| C. | remains constant. |
| D. | may increase or decrease ; depends on the chemical characteristics of polluted water. |
| Answer» B. increases. | |
| 10. |
Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundaries causes |
| A. | asphyxiation (suffocation). |
| B. | shortness of breath. |
| C. | tuberculosis. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 11. |
Disinfection of water is done to remove |
| A. | color |
| B. | bad taste |
| C. | foul odour |
| D. | bacteria |
| Answer» E. | |
| 12. |
Insufficient washing of sand grains in a rapid sand filter causes |
| A. | air binding |
| B. | shrinkage of filtering media |
| C. | mud balls |
| D. | expansion of filtering media |
| Answer» D. expansion of filtering media | |
| 13. |
Which of the following plants does not emit appreciable amount of SO₂ in atmosphere ? |
| A. | Thermal power plant |
| B. | Petroleum refinery |
| C. | Nitric acid plant |
| D. | Sulphuric acid plant |
| Answer» D. Sulphuric acid plant | |
| 14. |
Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about __________ decibels. |
| A. | 75 |
| B. | 95 |
| C. | 120 |
| D. | 140 |
| Answer» C. 120 | |
| 15. |
Noise level in a quiet private business office is about __________ decibels. |
| A. | 25 |
| B. | 50 |
| C. | 70 |
| D. | 85 |
| Answer» C. 70 | |
| 16. |
Soluble silica present in boiler feed water can be removed by |
| A. | coagulation |
| B. | filtration |
| C. | anion exchanger |
| D. | preheating it |
| Answer» D. preheating it | |
| 17. |
Which is the most efficient dust removal equipment for removal of sub-micronic dust particles from blast furnace gas ? |
| A. | Packed scrubber |
| B. | Gravity settling chamber |
| C. | Electrostatic precipitator |
| D. | Hydrocyclone |
| Answer» D. Hydrocyclone | |
| 18. |
__________ plant emits large amount of SO₂ as an air pollutant. |
| A. | Nitric acid |
| B. | Sulphuric acid |
| C. | Chloralkali |
| D. | Iron & steel |
| Answer» C. Chloralkali | |
| 19. |
Beyond what concentration of H₂S in air, acute danger to human life exists ? |
| A. | 50 ppm |
| B. | 100 ppm |
| C. | 300 ppm |
| D. | 700 ppm |
| Answer» E. | |
| 20. |
A shallow pond in which the sewage is retained and biologically treated is called |
| A. | oxidation |
| B. | Imhoff tank |
| C. | lagoon |
| D. | skimming tank |
| Answer» B. Imhoff tank | |
| 21. |
Which of the following fine dust removal equipments is the most efficient ? |
| A. | Bag filter |
| B. | Scrubber |
| C. | Electrostatic precipitator |
| D. | Cyclone separator |
| Answer» D. Cyclone separator | |
| 22. |
During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank. |
| A. | filtration |
| B. | digestion |
| C. | sedimentation |
| D. | both (b) and (c) |
| Answer» E. | |
| 23. |
Acute danger to human life (i.e. death) exists, if the concentration of CO₂ in atmospheric air exceeds __________ percent (by volume). |
| A. | 1 |
| B. | 3 |
| C. | 7 |
| D. | 20 |
| Answer» E. | |
| 24. |
Ozone level is generally found to be depleted in India in the month of |
| A. | February |
| B. | July |
| C. | April |
| D. | December |
| Answer» E. | |
| 25. |
The progressive warming up of the earth's surface is mainly due to the |
| A. | automobile exhaust. |
| B. | blanketing effect of CO₂ in the atmosphere. |
| C. | de-forestation. |
| D. | thickening of ozone layer. |
| Answer» C. de-forestation. | |
| 26. |
Which of the following is not a natural source of air pollution ? |
| A. | Volcanic eruptions and lightening discharges. |
| B. | Biological decay of vegetable matter. |
| C. | Photochemical oxidation of organic matter. |
| D. | None of these. |
| Answer» E. | |
| 27. |
Noise pollution level in a chemical plant is expressed in |
| A. | roentgen |
| B. | decibel |
| C. | hertz |
| D. | none of these |
| Answer» C. hertz | |
| 28. |
Death may occur, when SO₂ concentration in atmospheric air exceeds __________ ppm. |
| A. | 20 |
| B. | 100 |
| C. | 400 |
| D. | 200 |
| Answer» D. 200 | |
| 29. |
Most efficient and suitable dust removal equipment for removal of flyash from flue gas in a thermal power plant is the |
| A. | gravity settling chamber |
| B. | cyclone separator |
| C. | electrostatic precipitator |
| D. | bag filter |
| Answer» D. bag filter | |
| 30. |
Limestone powder is injected during pulverised coal burning in boilers to __________ the flue gases. |
| A. | reduce SO₂ content in |
| B. | catalytically convert SO₂ to SO₃ in |
| C. | increase the dew point of |
| D. | none of these. |
| Answer» B. catalytically convert SO₂ to SO₃ in | |
| 31. |
Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about __________ decibels. |
| A. | 90 |
| B. | 120 |
| C. | 150 |
| D. | 180 |
| Answer» C. 150 | |
| 32. |
Which is the most widely used coagulant for the treatment of turbid water ? |
| A. | Alum (aluminium sulphate) |
| B. | Lime |
| C. | Ferric chloride |
| D. | Sodium aluminate |
| Answer» B. Lime | |
| 33. |
Radioactive solid nuclear wastes are disposed off by |
| A. | high temperature incineration. |
| B. | pathological incineration. |
| C. | pyrolysis. |
| D. | underground burial in concrete containers. |
| Answer» E. | |
| 34. |
Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace. |
| A. | low amount of excess combustion air |
| B. | large quantity of excess combustion air |
| C. | hydrocarbon fuel |
| D. | pulverised coal as fuel |
| Answer» B. large quantity of excess combustion air | |
| 35. |
Threshold limit value (TLV) of CO in air is __________ ppm. |
| A. | 5 |
| B. | 50 |
| C. | 2000 |
| D. | 5000 |
| Answer» C. 2000 | |
| 36. |
Which of the following is the most severe air pollutant ? |
| A. | hydrocarbons |
| B. | Noₓ |
| C. | SO₂ |
| D. | CO |
| Answer» C. SO₂ | |
| 37. |
Arsenic pollutant is not generated in____industries. |
| A. | tanneries |
| B. | glass & ceramic |
| C. | beverages |
| D. | any of these. |
| Answer» D. any of these. | |
| 38. |
In large thermal power stations very fine particulates present in flue gas are removed by |
| A. | wet scrubber |
| B. | bag filter |
| C. | electrostatic precipitators |
| D. | dust catcher |
| Answer» D. dust catcher | |
| 39. |
Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst for |
| A. | conversion of CO into CO₂ in the second compartment. |
| B. | conversion of NOₓ into N₂ and NH₃ in the first compartment. |
| C. | oxidation of unburnt hydrocarbon fuel in the second compartment. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 40. |
Peroxyacyl nitrate (PAN), a pollutant is found in the |
| A. | automobile exhaust. |
| B. | flue gas of coal based power plant. |
| C. | exhaust of nitric acid plant. |
| D. | exhaust of sulphuric acid plant. |
| Answer» B. flue gas of coal based power plant. | |
| 41. |
TLV of aldrin in public water supply system is about __________ μg/litre. |
| A. | 0.5 |
| B. | 17 |
| C. | 357 |
| D. | 1097 |
| Answer» C. 357 | |
| 42. |
A standard test for determination of hardness in water is termed as __________ test. |
| A. | EDTA |
| B. | electometric |
| C. | total count |
| D. | presumptive |
| Answer» B. electometric | |
| 43. |
Fresh sewage is __________ in nature. |
| A. | acidic |
| B. | neutral |
| C. | alkaline |
| D. | highly acidic |
| Answer» D. highly acidic | |
| 44. |
Which of the following is a secondary air pollutant ? |
| A. | Photochemical smog |
| B. | Sulphur dioxide |
| C. | Nitrogen dioxide |
| D. | Dust particles |
| Answer» B. Sulphur dioxide | |
| 45. |
Which of the following is the most lethal water pollutant ? |
| A. | Phenol and cynide |
| B. | Chlorine |
| C. | Alkalis |
| D. | Suspended solids |
| Answer» B. Chlorine | |
| 46. |
Septic tanks are used for the __________ of the deposited solids. |
| A. | separation |
| B. | anaerobic decomposition |
| C. | aerobic decomposition |
| D. | none of these |
| Answer» C. aerobic decomposition | |
| 47. |
__________ can not control the noise pollution. |
| A. | Use of silencers |
| B. | Green house gases |
| C. | Vibration damping |
| D. | Tree plantation |
| Answer» C. Vibration damping | |
| 48. |
Removal of __________ is accomplished by aeration of water. |
| A. | dissolved gases |
| B. | suspended solids |
| C. | dissolved solids |
| D. | none of these |
| Answer» B. suspended solids | |
| 49. |
Particles having diameter greater than 75 μm (micrometer = 10⁻⁶ mm) are called |
| A. | grit |
| B. | dust |
| C. | powder |
| D. | smoke |
| Answer» B. dust | |
| 50. |
Solid content in most of the domestic sewage is about __________ percent. |
| A. | 0.001 |
| B. | 0.1 |
| C. | 5 |
| D. | 10 |
| Answer» C. 5 | |