Name some devices to separate particulate matter from the polluted air.

Particulate and gaseous pollutatnts alongwith harmless gases are released form the thermal power plants: Name the most widely used device of removing particulate pollutants from the air. Explain how the device is used.

Name the technique to separate : Salt from sea water

Name the technique to separate : Salt from sea water

Name the technique to separate : Butter from curd