What are particulate matter?

Which one of the following is not a device used to control a particulate matter ?

Which one of the following is a most efficient device to eliminate particulate matters form the industrial emission ?

Which of the following is a method used to get rid of particulate matter present in the exhaust from a thermal power plant ?

What are particulate pollutants ? Explain any three.

Read the following statements carefully. (i) An electrostatic precipitator removes particulate matter by imposing negative charge on them. (ii) Catalytic converters convert unburnt hydrocarbons into CO_(2) and water. (iii) Peroxyacyl nitrates (PAN) is a secondary pollutant. (iv) DDT is a non-biodegradable pollutant. Which of the above statements are incorrect ?