NPTEL Air Pollution and Control Assignment 9 Answers 2022

NPTEL Air Pollution and Control Assignment 9

Are you looking for the Answers to NPTEL Air Pollution and Control Assignment 9? This article will help you with the answer to the National Programme on Technology Enhanced Learning (NPTEL) Course “ NPTEL Air Pollution and Control Assignment 9 “

What is Air Pollution and Control?

The objective of the course is to impart the knowledge and understanding of causes and effects of air pollution and their controlling mechanisms. The course will provide a deeper understanding of air pollutants, pollution inventory and modelling. The course also imparts knowledge on the impacts of air pollution on different aspects such as policy, human health and various contemporary technological innovation for betterment of air quality.


Average assignment score = 25% of the average of best 8 assignments out of the total 12 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF THE AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.

Below you can find the answers for NPTEL Air Pollution and Control Assignment 9

Assignment No.Answers
Air Pollution Assignment 1 Click Here
Air Pollution Assignment 2 Click Here
Air Pollution Assignment 3 Click Here
Air Pollution Assignment 4 Click Here
Air Pollution Assignment 5 Click Here
Air Pollution Assignment 6 Click Here
Air Pollution Assignment 7 Click Here
Air Pollution Assignment 8 Click Here

NPTEL Air Pollution and Control Assignment 9 Answers:-

Q1. Which of the following devices is not used to control gases from stationary sources?

a. Spray tower 
b. Packed towers 
c. Venturi-scrubbers 
d. Fabric filters

Answer:- d. Fabric filters

Q2. Select the suitable device used to control industrial dust emissions?

  • Settling Chamber 
  • Catalytic converter 
  • Positive crankcase ventilation valve 
  • All of the above

Answer: a. Settling Chamber 

Q3. From the cost and removal efficiency perspective, which of the following pollutant control devices is preferred for effective removal of the particulates above 40 µm in size?

  • Inertial Separators 
  • Cyclonic Separators 
  • Settling Chamber 
  • Electrostatic Precipitators

Answer: c. Settling Chamber 

Q4. What is the principal particle collection mechanism used in venturi scrubbers?

  • Brownian motion 
  • Electrostatic attraction 
  • Inertial impaction  
  • Coagulation

Answer: c. Inertial impaction  

Next Week Assignment Answers

quizxp telegram

Q5. Which of the following statements is incorrect for the fabric filter?

  • Cleaning is required at regular intervals for efficient operation. 
  • Improper filter media increases the collection efficiency. 
  • The normal velocity of airflow through the bags is 0.4-1 m/min. 
  • The air-to-cloth ratio is the main sizing parameter used for the fabric filter.

Answer: b. Improper filter media increases the collection efficiency. 

Q6. The collection efficiency of the ESP is given by the Deutch-Anderson equation, when η = fractional collection efficiency, ω = drift velocity (m/sec), A = Available collection area, (m2), Q = volumetric flow rate (m3/sec)

Answer:- c

If there are any changes in answers will notify you on telegram so you can get a 100% score, So Join

Q7. The quantity of recirculation liquid used in the absorber divided by the outlet gas flow rate is called______________.

  • Gas-to-liquid ratio 
  • Absorption efficiency  
  • Liquid-to-gas ratio 
  • Adsorption efficiency

Answer: c. Liquid-to-gas ratio 

Q8. Biofiltration can be classified as a special type of absorption system using _____________processes to control the gaseous contaminant.

  • Reversible 
  • Irreversible 
  • Equilibrium  
  • Reversible and irreversible 

Answer: b. Irreversible 

Q9. Which of the following primary forces is responsible for the particle collection in cyclone collectors?

  • Electrostatic 
  • Brownian Diffusion 
  • Centrifugal 
  • Gravitational 

Answer: c. Centrifugal 

Q10. Which device is fitted in vehicles to control air pollution from the tailpipe emissions:

  • Electrostatic precipitator 
  • Catalytic converter 
  • Bag filter 
  • Cyclone separator

Answer: b. Catalytic converter 

For other courses answers:- Visit

For Internship and job updates:- Visit

Disclaimer: We do not claim 100% surety of answers, these answers are based on our sole knowledge, and by posting these answers we are just trying to help students, so we urge do your assignment on your own.

if you have any suggestions then comment below or contact us at [email protected]

If you found this article Interesting and helpful, don’t forget to share it with your friends to get this information.

NPTEL Air Pollution and Control Assignment 9 Answers 2022:- All the Answers provided here to help the students as a reference, You must submit your assignment at your own knowledge.