Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

Infective bacteria in water is killed by the _____________ process?

A. Sterilisation
B. Aeration
C. Disinfection
D. None of these
Answer» B. Aeration
2.

Industrial workers working in leather tanning & manufacturing units are prone to suffer from ___________________?

A. Respiratory ailments (e.g. bronchitis)
B. Skin diseases (e.g. dermatitis)
C. Silicosis
D. Blurred vision
Answer» C. Silicosis
3.

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
4.

In water treatment, alum [Al2(SO4)3] is used for the process of __________________?

A. Filtration
B. Coagulation
C. Sedimentation
D. Disinfection
Answer» C. Sedimentation
5.

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
6.

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
7.

In sewage treatment, the detention period allowed for oxidation ponds ranges from _____________ weeks?

A. 1 to 2
B. 4 to 5
C. 9 to 10
D. 15 to 20
Answer» C. 9 to 10
8.

In sewage treatment, its sedimentation is speeded up by commonly adding__________________?

A. Hydrochloric acid
B. Lime
C. Copper sulphate
D. Sodium sulphate
Answer» C. Copper sulphate
9.

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
10.

In a sedimentation tank, the detention period for water ranges from _____________ hours?

A. 2 to 4
B. 8 to 12
C. 16 to 20
D. 24 to 32
Answer» B. 8 to 12
11.

Hydrogen ion concentration in distilled water is___________________?

A. 10-7
B. 7 × 10-7
C. 107
D. 7 × 107
Answer» B. 7 × 10-7
12.

Higher concentration of nitrogen dioxide in atmospheric air causes___________________?

A. Cancer
B. Bronchitis
C. Asphyxiation
D. Corrosion
Answer» C. Asphyxiation
13.

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.
14.

High noise levels produced during operation of fans and compressors can be reduced by using__________________?

A. Mufflers (silencers)
B. Acoustic absorbent
C. Lagging of noisy duct
D. None of these
Answer» B. Acoustic absorbent
15.

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.
16.

High concentration of carcinogenic hydrocarbon pollutants in atmospheric air causes____________________?

A. Cancer
B. Silicosis
C. Respiratory disease (e.g., asthma)
D. Reduced crop yield
Answer» B. Silicosis
17.

Hazardous/polluting chemical industries should have an ‘exclusion zone’ with a green belt and general public access prohibited around it, covering a radius of _____________ metres?

A. 100
B. 1000
C. 400
D. 4000
Answer» C. 400
18.

H2S present in gaseous stream can be removed by adsorption on _____________________?

A. Silica gel
B. Active carbon
C. Bog iron
D. Limestone powder
Answer» D. Limestone powder
19.

Growth of ______________ is promoted by the presence of manganese in water?

A. Files
B. Algae
C. Micro-organisms
D. Mosquitoes
Answer» D. Mosquitoes
20.

Green house gases blanket/block the infrared radiation from earth’s surface to the atmosphere leading to its progressive warming up. Which of the following gases does not exhibit green house effect ?

A. CO2
B. H2
C. SO3
D. N2
Answer» D. N2
21.

Green house effect is accentuated by________________?

A. Deforestation
B. Rapid industrialisation
C. Increased transportation activity
D. All A., B. and C.
Answer» E.
22.

Global warming may result in __________________?

A. Flood
B. Cyclone
C. Decrease in food productivity
D. All A., B. and C.
Answer» E.
23.

From pollution control point of view, the maximum permissible concentration of sulphur dioxide in atmospheric air is about ________________ ppm?

A. 5
B. 50
C. 500
D. 5000
Answer» B. 50
24.

Fresh sewage is ______________ in nature?

A. Acidic
B. Neutral
C. Alkaline
D. Highly acidic
Answer» D. Highly acidic
25.

Fresh domestic sewage is _______________ in color?

A. Grey
B. Dark brown
C. Red
D. Black
Answer» B. Dark brown
26.

Foul odour and bad taste of water is removed by treating with__________________?

A. Alum
B. Bleaching powder
C. Activated carbon
D. Copper sulphate
Answer» D. Copper sulphate
27.

For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than ______________ ppm?

A. 10000
B. 5
C. 500
D. 1000
Answer» C. 500
28.

Foaming and priming in boiler operation can be reduced by reduction in ______________ in feed water?

A. Turbidity
B. Color (Hazen)
C. Total solids
D. All A., B. & C.
Answer» E.
29.

Fluorosis is caused due to the presence of excessive amount of ______________ in drinking water?

A. Mercury
B. Lead
C. Fluoride
D. Arsenic
Answer» D. Arsenic
30.

Fluorosis (a bone disease) is caused by the presence of high concentration of ____________ in atmospheric air?

A. Hydrocarbons
B. Hydrogen fluoride
C. Hydrogen sulphides
D. Nitrogen dioxide
Answer» C. Hydrogen sulphides
31.

Fine grit present in sewage is removed in the _____________ during sewage treatment?

A. Grit chamber
B. Detritus tank
C. Trickling filter
D. Skimming tank
Answer» C. Trickling filter
32.

Exposure to small amount of ______________ results in high blood pressure & heart disease in human beings?

A. Hydrogen sulphide
B. Mercury
C. Cadmium
D. Asbestos
Answer» D. Asbestos
33.

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.
34.

Exposure to chemicals having carcinogenic properties cause___________________?

A. Dermatitis (skin disorder)
B. Cancer
C. Asphyxiation
D. Asthma
Answer» C. Asphyxiation
35.

Exposure to chemicals having carcinogenic properties cause ____________________?

A. Dermatitis (skin disorder)
B. Cancer
C. Asphyxiation (suffocation)
D. Asthma
Answer» C. Asphyxiation (suffocation)
36.

Ethanolamine is an absorbent used for the removal of _____________ from air/gas?

A. HF
B. SO2
C. H2S
D. Both B. & C.
Answer» E.
37.

Dust collection efficiency of a cyclone separator depends upon its______________?

A. Diameter
B. Inlet gas velocity
C. Overall height
D. All A., B. & C.
Answer» E.
38.

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.
39.

Dissolved oxygen content in river water is around _____________ ppm?

A. 5
B. 100
C. 250
D. 500
Answer» B. 100
40.

Disinfection of water is done to remove ______________________?

A. Color
B. Bad taste
C. Foul odour
D. Bacteria
Answer» E.
41.

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.
42.

Direct reaction of unsaturated hydrocarbons with either NO or NO2 produces an eye irritating pollutant compound known as________________?

A. Photochemical smog
B. Peroxyacetyl nitrate (PAN) or methyl nitrite
C. Benzopyrene
D. Polyacrylonitrile
Answer» C. Benzopyrene
43.

Death may occur, when SO2 concentration in atmospheric air exceeds ______________ ppm?

A. 20
B. 100
C. 400
D. 200
Answer» D. 200
44.

Deaeration of high pressure boiler feed water is done to reduce ___________________?

A. Foaming from boilers
B. Its dissolved oxygen content
C. Its silica content
D. Caustic embrittlement
Answer» C. Its silica content
45.

Corrosion in boilers can be prevented by _________________?

A. Deaeration of feed water
B. Enhancing pH of feed water by adding alkali
C. Feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion
D. All A., B. and C.
Answer» E.
46.

______________ content of the phosphate rock is the pollutant of primary interest in a phosphatic fertiliser plant ?

A. Calcium
B. Fluorine
C. Phosphorous
D. Sulphur
Answer» C. Phosphorous
47.

Color test of water is done with an instrument called__________________?

A. Tintometer
B. Colorimeter
C. Electro-chemical cell
D. Turbidimeter
Answer» B. Colorimeter
48.

COD of raw municipal sewage may be in the range of about _____________ mg/litre?

A. 1-2
B. 5-10
C. 90-120
D. 1500-2500
Answer» D. 1500-2500
49.

Coal washing waste water containing about 3% suspended solids (comprising of clay, slate, stone etc.) is treated for solid particles removal ?

A. By chemical coagulation
B. In sedimentation tanks equipped with mechanical scrapper
C. In vacuum filter
D. In clarifiers
Answer» C. In vacuum filter
50.

CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing ________________ molecules of ozone?

A. 102
B. 105
C. 109
D. 1015
Answer» C. 109