MCQOPTIONS
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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.
| 251. |
In troposphere (the weather domain), the temperature 't' at height 'h' above the spa level in metres is given by (where, temperature at sea level is 15°C and t is in °C.) |
| A. | t = 15 - 0.0065h |
| B. | t = 15 + 0.0065h |
| C. | t = 0.0035h -15 |
| D. | t = 15 - 0.0035h |
| Answer» B. t = 15 + 0.0065h | |
| 252. |
Higher concentration of CO₂ in atmosphere |
| A. | allows visible solar radiation (ultraviolet) of short wave-length to pass through. |
| B. | reflects and absorbs the longer wavelength (infra-red) radiations. |
| C. | prevents solar heat being radiated out completely, resulting in 'heat trap' i.e., global warming. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 253. |
Main pollutants released from petroleum refineries is |
| A. | CO, SO₂ & H₂S. |
| B. | CO₂, NO & SO₃. |
| C. | CO₂, H₂S & NO₂. |
| D. | SO₃, NO₂ & CO₂. |
| Answer» B. CO₂, NO & SO₃. | |
| 254. |
Which of the following is an adsorbant for removal of nitrogen oxides from gas/air ? |
| A. | Active carbon |
| B. | Silica gel |
| C. | Bog iron (iron oxide) |
| D. | Pulverised limestone |
| Answer» C. Bog iron (iron oxide) | |
| 255. |
Presence of carbon monoxide in atmosphere produced by decomposition of chlorophyl and haemoglobin breakdown of some animals, beyond TLV (>50 ppm) |
| A. | acts as a green house gas thereby raising earth's temperature. |
| B. | causes asphyxia. |
| C. | causes increase in sea level. |
| D. | inhances the green house effect. |
| Answer» C. causes increase in sea level. | |
| 256. |
Which is the most practical and economical method for removal of suspended solid matter from polluted water ? |
| A. | Sedimentation |
| B. | Skimming off |
| C. | Chlorination |
| D. | Biological oxidation |
| Answer» B. Skimming off | |
| 257. |
What are the methods of treatment & disposal of radioactive wastes ? |
| A. | Evaporation & chemical precipitation. |
| B. | Biological methods & adsorption in ion exchange materials. |
| C. | Fixing into a solid mass with cement and sinking deep in the sea. |
| D. | All (a), (b) & (c). |
| Answer» E. | |
| 258. |
Atmospheric pollution caused by the exhaust gas of supresonic transport air-crafts is mostly in the atmospheric region called |
| A. | thermosphere |
| B. | stratosphere |
| C. | troposphere |
| D. | mesosphere |
| Answer» C. troposphere | |
| 259. |
Noise level heard at a distance of about 100 metres from a jet engine with after burner is about __________ decibels. |
| A. | 120 |
| B. | 140 |
| C. | 170 |
| D. | 200 |
| Answer» D. 200 | |
| 260. |
Methyl iso-cynate (MIC) gas (TLV |
| A. | moderately |
| B. | highly |
| C. | extremely |
| D. | very extremely |
| Answer» E. | |
| 261. |
Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of |
| A. | ozone and iodine. |
| B. | chlorine or its compounds. |
| C. | ultraviolet light for irradiation of water. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 262. |
In water chemical treatment plant, use of chloramines ensures |
| A. | disinfection. |
| B. | taste & odour control. |
| C. | weed control in reservoirs. |
| D. | removal of permanent hardness. |
| Answer» B. taste & odour control. | |
| 263. |
Direct reaction of unsaturated hydrocarbons with either NO or NO₂ produces an eye irritating pollutant compound known as |
| A. | photochemical smog. |
| B. | peroxy acetyl nitrate (PAN) or methyl nitrile. |
| C. | benzopyrene. |
| D. | poly acrylonitrile |
| Answer» C. benzopyrene. | |
| 264. |
Industrial workers working in leather tanning & manufacturing units are prone to suffer from |
| A. | respirtory ailments (e.g. bronchitis). |
| B. | skin diseases (e.g. dermatities). |
| C. | silicosis. |
| D. | blurred vision. |
| Answer» C. silicosis. | |
| 265. |
Lung cancer & DNA breakage are the major ill effects of excessive ozone exposure to human beings. Ozone layer depletion in the atmosphere is mainly caused by the presence of |
| A. | CO₂ |
| B. | SO₂ |
| C. | hydrocarbons |
| D. | CFC (chloro fluoro carbon) |
| Answer» E. | |
| 266. |
__________ substances present in sewage are removed in grit chamber during sewage treatment. |
| A. | Organic |
| B. | Fatty |
| C. | Inorganic |
| D. | Dissolved |
| Answer» D. Dissolved | |
| 267. |
From pollution control point of view, the maximum permissible concentration of sulphur dioxide in atmospheric air is about __________ ppm. |
| A. | 1 |
| B. | 5 |
| C. | 50 |
| D. | 500 |
| Answer» C. 50 | |
| 268. |
High noise level in a chemical plant can be controlled by the |
| A. | suppression of noise at the source itself. |
| B. | path control of noise. |
| C. | protection of operating personnel. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 269. |
Most of the atmospheric air pollutants are present in large quantity in |
| A. | stratosphere |
| B. | thermosphere |
| C. | trophosphere |
| D. | mesosphere |
| Answer» D. mesosphere | |
| 270. |
Exposure to SO₂ containing chimney gases results in the |
| A. | reduction in strength of leather & cloth. |
| B. | acceleration of corrosion rates of metals. |
| C. | increased drying & hardening time of paints. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 271. |
Which of the following is not a source of ozone emission in the atmosphere ? |
| A. | Refrigerators. |
| B. | Xerox machines. |
| C. | Dermatological photo-therapy equipments. |
| D. | High voltage electrical equipments. |
| Answer» B. Xerox machines. | |
| 272. |
Global warming may result in |
| A. | flood |
| B. | cyclone |
| C. | decrease in food productivity |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 273. |
Very small amount of air pollutants are present in stratosphere also; though most of the atmospheric pollutants are present in the troposphere. Which of the following atmospheric pollutants does not cause the ozone layer depletion in atmosphere at tremendous rate ? |
| A. | CO |
| B. | SO₂ |
| C. | Noₓ |
| D. | CFC (chloro fluoro carbons) |
| Answer» B. SO₂ | |
| 274. |
Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes |
| A. | fading of dyes on textiles. |
| B. | corrosion, tarnishing & soiling of metals. |
| C. | reduced strength of textiles. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 275. |
Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre)? |
| A. | Lagooning |
| B. | Activated carbon adsorption |
| C. | Biological oxidation pond |
| D. | Chemical coagulation |
| Answer» C. Biological oxidation pond | |
| 276. |
The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about __________ decibels. |
| A. | 60 |
| B. | 90 |
| C. | 105 |
| D. | 120 |
| Answer» C. 105 | |
| 277. |
The main pollutant in waste water discharged from a petroleum refinery is oil (both in free and emulsified form). Free oil is removed by |
| A. | biological oxygen pond. |
| B. | aerated lagoons. |
| C. | trickling filters. |
| D. | gravity separator having oil skimming devices. |
| Answer» E. | |
| 278. |
As per the world health organisation (WHO) specification, the maximum permissible concentration (i.e., TLV) of particulate matter in air is __________ μg/m³.(μg-microgram) |
| A. | 10 |
| B. | 90 |
| C. | 800 |
| D. | 750 |
| Answer» C. 800 | |
| 279. |
Radioactive substances present in the polluted water stream can be removed by |
| A. | biological oxygen treatment. |
| B. | coagulation and filtration. |
| C. | adsorption in ion exchange materials. |
| D. | none of these. |
| Answer» D. none of these. | |
| 280. |
In water treatment plant, zeolite process is used to remove the __________ of water. |
| A. | acidity |
| B. | alkalinity |
| C. | hardness |
| D. | iron & zinc |
| Answer» D. iron & zinc | |
| 281. |
Green house effect is accentuated by |
| A. | deforestation. |
| B. | rapid industrialisation. |
| C. | increased transportation activity. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 282. |
Presence of dissolved impurities of __________ is responsible for the red brownish color of water. |
| A. | carbonates |
| B. | bi-carbonates |
| C. | iron & manganese |
| D. | arsenic |
| Answer» D. arsenic | |
| 283. |
In the context of the chemical process industries, the term BOD is normally associated with the |
| A. | characterisation of solid wastes. |
| B. | organic concentration in gaseous effluents. |
| C. | characterisation of liquid effluents. |
| D. | characterisation of boiler feed water. |
| Answer» D. characterisation of boiler feed water. | |
| 284. |
Growth of __________ is promoted by the presence of manganese in water. |
| A. | files |
| B. | algae |
| C. | micro-organisms |
| D. | mosquitoes |
| Answer» D. mosquitoes | |
| 285. |
Maximum permissible limit of mercury in human blood is __________ micrograms/100 c.c. |
| A. | 1 |
| B. | 7 |
| C. | 19 |
| D. | 82 |
| Answer» C. 19 | |
| 286. |
Lead exhausted in the atmosphere by automobiles using leaded petrol (i.e. tetraethyl lead for improving octane number) is a lethal air pollutant which causes |
| A. | paralysis of muscles & loss of appetite. |
| B. | nervous depression. |
| C. | gastritis & diarrhea. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 287. |
Pick out the wrong statement pertaining to 'green house' for the plants. |
| A. | 'Green house' (made of glass) allows visible sunlight (i.e., short wavelength solar radiation like ultra-violet rays) to pass through the glass and heat up the soil thereby warming up plants inside it. |
| B. | The emitted longer wavelength radiation (e.g., infrared) is partly reflected and partly absorbed by the glass of the green house. |
| C. | Green house effect' in earth's atmosphere is due to increasing CO₂ level in atmosphere. where CO₂ acts like the glass of 'green house' thereby warming up the earth's surface. |
| D. | 'Green house' is colder than the outside atmosphere. |
| Answer» E. | |
| 288. |
Polyvinyl chloride containers are not suitable for storing |
| A. | foodstuffs |
| B. | woolen clothes |
| C. | metallic powder |
| D. | none of these |
| Answer» B. woolen clothes | |
| 289. |
There are five concentric layers within the atmosphere which is differentiated on the basis of temperature. The atmospheric layer which lies close to the earth's surface in which human being along with other organisms live is called troposphere. The rate at which air temperature in the troposphere gradually decreases with height is about __________ °C/km. |
| A. | 0.05 |
| B. | 1 |
| C. | 6.5 |
| D. | 15 |
| Answer» D. 15 | |
| 290. |
Main pollutants released from iron & steel industry is |
| A. | CO, CO₂ & SO₂. |
| B. | H₂S, NO & SO₃. |
| C. | CO₂, H₂S & NO₂. |
| D. | SO₃, NO₂ & CO₂. |
| Answer» B. H₂S, NO & SO₃. | |
| 291. |
Exposure to chemicals having carcinogenic properties cause |
| A. | dermatitis (skin disorder) |
| B. | cancer |
| C. | asphyxiation (suffocation) |
| D. | asthma |
| Answer» C. asphyxiation (suffocation) | |
| 292. |
Fluorosis (a bone disease) is caused by the presence of high concentration of __________ in atmospheric air. |
| A. | hydrocarbons |
| B. | hydrogen flouride |
| C. | hydrogen sulphides |
| D. | nitrogen dioxide |
| Answer» C. hydrogen sulphides | |
| 293. |
Threshold Limit Value (TLV) is the maximum allowable concentration (i.e. safe limit) of pollutants in air. Safe limit for SO₂ in air is __________ ppm. |
| A. | 5 |
| B. | 500 |
| C. | 1000 |
| D. | 2000 |
| Answer» B. 500 | |
| 294. |
Smoke is produced due to |
| A. | insufficient supply of combustion air and insufficient time for combustion. |
| B. | poor quality of fuel and improper mixing of fuel & combustion air. |
| C. | poor design & overloading of furnace. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 295. |
A 40% gas in a system has partial pressure 4 atm, what is Henry’s constant? |
| A. | 1.6 atm |
| B. | 4 atm |
| C. | 10 atm |
| D. | 16 atm |
| Answer» D. 16 atm | |
| 296. |
What is the K value of a gas with partial pressure 50 Pa and the total pressure of the system is 1 mm Hg? |
| A. | 0.37 |
| B. | 0.45 |
| C. | 0.79 |
| D. | 0.91 |
| Answer» B. 0.45 | |
| 297. |
What is the partial pressure of a 70% gas in a system, if H = 5 mm Hg? |
| A. | 3.5 mm Hg |
| B. | 7 mm Hg |
| C. | 14 mm Hg |
| D. | 35 mm Hg |
| Answer» B. 7 mm Hg | |
| 298. |
What is the vapor pressure of 50% gas in a system with partial pressure 2 mm Hg? |
| A. | 1 mm Hg |
| B. | 2 mm Hg |
| C. | 4 mm Hg |
| D. | 8 mm Hg |
| Answer» D. 8 mm Hg | |
| 299. |
What is the partial pressure of a 40% gas in a system with vapor pressure 1 mm Hg? |
| A. | 0.2 mm Hg |
| B. | 0.4 mm Hg |
| C. | 0.6 mm Hg |
| D. | 0.8 mm Hg |
| Answer» C. 0.6 mm Hg | |