In an electrostatic precipitator, the electrode wires produce a corona that releases which of the following to make dust particles get attracted to the collecting plates?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Electrons
Option (2) Electrons — Correct. Electrons attach to dust particles, giving them a negative charge, and the grounded plates attract them.
Note: This question is from Chapter 16, Environmental Issues, of the pre-rationalised NCERT book. This chapter is not in the present NCERT book (2026-27). The extract below is from the pre-rationalised edition.
NCERT Extract (Pre-rationalised edition, Chapter 16, Environmental Issues):
Air Pollution and Its Control – “… There are several ways of removing particulate matter; the most widely used of which is the electrostatic precipitator (Figure 16.1), which can remove over 99 per cent particulate matter present in the exhaust from a thermal power plant. It has electrode wires that are maintained at several thousand volts, which produce a corona that releases electrons. These electrons attach to dust particles giving them a net negative charge. The collecting plates are grounded and attract the charged dust particles.”
