Explore topic-wise MCQs in Chemical Engineering.

This section includes 528 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.

501.

Infective bacteria in water is killed by the __________ process.

A. sterilisation
B. aeration
C. disinfection
D. none of these
Answer» B. aeration
502.

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
503.

Which of the following pollutants is absent in the emissions from a fertiliser plant ?

A. SO2 & SO3
B. NO2
C. NH3
D. CO
Answer» E.
504.

The type of bacteria which is active in trickling filter during biological treatment of sewage is the __________ bacteria.

A. anaerobic
B. saphrophytic
C. aerobic
D. parasitic
Answer» D. parasitic
505.

The concentration of water vapour in troposphere, which depends upon the altitude & temperature varies in the range of zero to __________ percent.

A. 1
B. 4
C. 8
D. 12
Answer» C. 8
506.

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
507.

Exposure to chemicals having carcinogenic properties cause

A. dermatitis (skin disorder)
B. cancer
C. asphyxiation (suffocation)
D. asthma
Answer» C. asphyxiation (suffocation)
508.

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
509.

Smog is

A. nothing but black smoke.
B. a combination of smoke and fog.
C. a liquid particle resulting from vapor condensation.
D. a solid particle e.g. flyash.
Answer» C. a liquid particle resulting from vapor condensation.
510.

Most of the atmospheric air pollutants are present in large quantity in

A. stratosphere
B. thermosphere
C. trophosphere
D. mesosphere
Answer» D. mesosphere
511.

Persons working in cement plants and limestone quarries are more prone to disease like

A. cancer
B. asthma
C. silicosis
D. flourosis (bone disease)
Answer» D. flourosis (bone disease)
512.

During which of the following operating conditions of an automobile, carbon monoxide content in the exhaust gas is maximum ?

A. Idle running
B. Acceleration
C. Cruising
D. Deaccelaration
Answer» B. Acceleration
513.

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
514.

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.
515.

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
516.

Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called

A. fumes
B. mists
C. smoke
D. aerosols
Answer» E.
517.

Maximum allowable concentration of CO2 in air for safe working is __________ ppm (parts per million).

A. 50
B. 1000
C. 2000
D. 5000
Answer» E.
518.

The term Biological Oxygen Demand (BOD) is used in relation to

A. potable water
B. cooling water
C. distilled water
D. industrial effluents
Answer» E.
519.

Which of the following is the most detrimental for water used in high pressure boiler ?

A. Silica
B. Turbidity
C. Phenol
D. Dissolved oxygen
Answer» B. Turbidity
520.

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
521.

Operating principle of cyclone separator is based on the action of __________ dust particles.

A. diffusion of
B. centrifugal force on
C. gravitational force on
D. electrostatic force on
Answer» C. gravitational force on
522.

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.
523.

Scale formation in boiler is controlled by

A. preheating of feed water.
B. reduction in hardness, silica & alumina in feed water.
C. keeping the pH value of feed water just below 7.
D. eliminating H2S in feed water.
Answer» C. keeping the pH value of feed water just below 7.
524.

The commonest form of iron & manganese found in ground water as pollutant is in the form of their

A. carbonates
B. bi-carbonates
C. chlorides
D. sulphides
Answer» C. chlorides
525.

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.
526.

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.
527.

Ionisation potential employed in the industrial electrostatic precipitator is of the order of

A. 30 to 70 kV DC
B. 30 to 70 kV AC
C. 230 V AC
D. 230 V DC
Answer» B. 30 to 70 kV AC
528.

Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by

A. biological oxygen pond.
B. radial settling tank (thickener) using coagulant (lime & ferrous sulphate).
C. lagoons.
D. filtration.
Answer» C. lagoons.