5681. Noise level heard at a distance of about 100 metres from a jet engine with after burner is about __________ decibels.
120
140
170
200
✅ The correct answer is option C.
Chemical Engineering
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5682. Smoke is produced due to
Insufficient supply of combustion air and insufficient time for combustion
Poor quality of fuel and improper mixing of fuel & combustion air
Poor design & overloading of furnace
All of the above
✅ The correct answer is option D.
5683. Industrial workers working in leather tanning & manufacturing units are prone to suffer from
Respirtory ailments (e.g. bronchitis)
Skin diseases (e.g. dermatities)
Silicosis
Blurred vision
✅ The correct answer is option B.
5684. Ionisation potential employed in the industrial electrostatic precipitator is of the order of
30 to 70 kV DC
30 to 70 kV AC
230 V AC
230 V DC
✅ The correct answer is option A.
5685. Which of the following is not an air pollutant?
Ozone
Carcinogens
Pesticides
Metallic powders
✅ The correct answer is option A.
5686. Septic tanks are used for the __________ of the deposited solids.
Separation
Anaerobic decomposition
Aerobic decomposition
None of these
✅ The correct answer is option B.
5687. Dust collection efficiency of a cyclone separator depends upon its
Diameter
Inlet gas velocity
Overall height
All of the above
✅ The correct answer is option D.
5688. The main industrial source of emission of hydrogen sulphide air pollutant is
Petroleum refineries
Coal based thermal power plants
Pulp and paper plant
Metallurgical roasting & smelting plant
✅ The correct answer is option B.
5689. Which of the following pollutants, if present in atmosphere is detectable by its odour?
CO
SO₂
NO₂
CO₂
✅ The correct answer is option B.
5690. Which of the following acts as a natural source of air pollution?
Forest fire
Deforestation
Volcanic eruption
None of these
✅ The correct answer is option C.