The most widely used method for removing particulate matter is not associated with which of the following ?

Options

A. Can remove `99%` of particulate matter
B. Produces a corona of electrons
C. Positive charge as acquired by dust particles
D. Velocity of air between collecting plates is low

Answer

To solve the question regarding the method for removing particulate matter that is not associated with a specific characteristic, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Method**: The most widely used method for removing particulate matter is the **electrostatic precipitator**. This device is commonly used in industries, especially in thermal power plants, to clean exhaust gases.

2. **Understand the Functioning of Electrostatic Precipitators**:
- The electrostatic precipitator can remove over **99% of particulate matter** from the exhaust.
- It uses **electrode wires** maintained at high voltages (several thousand volts) to produce a **corona discharge** that releases electrons.
- These electrons attach to the dust particles, giving them a **negative charge**.

3. **Collecting Plates**: The collecting plates in the electrostatic precipitator are grounded, which means they have a **positive charge** relative to the negatively charged dust particles. This causes the dust particles to be attracted to the plates.

4. **Velocity of Air**: The **velocity of air** between the collecting plates is kept low to allow the dust particles to settle down effectively.

5. **Analyze the Options**: The question asks for the characteristic that is **not associated** with the electrostatic precipitator. The options provided include:
- Can remove 99% of particulate matter
- Produces a corona of electrons
- Positive charge acquired by dust particles
- Velocity of air between collecting plates is low

6. **Identify the Incorrect Statement**: Among these options, the statement that is **not associated** with the electrostatic precipitator is:
- **Positive charge acquired by dust particles**. This is incorrect because the dust particles acquire a negative charge due to the attachment of electrons.

### Final Answer:
The characteristic that is **not associated** with the electrostatic precipitator is the **positive charge acquired by dust particles**.

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