Which of the following statement is INCORRECT.

Options

A. `(e)/(m)` ratio for canal rays is maximum for hydrogen ion.
B. `(e)/(m)` ratio for cathode rays is independent of the gas taken.
C. The nature of canal rays is dependent on the electrode material.
D. The `(e)/(m)` ratio for electron is expressed as `(E^(2))/(2B^(2)V)`, when the cathode rays go undeflected under the influence of electric field `(E)`, magnetic field `(B)` and `V` is potential difference applied across electrodes.

Explanation

To determine which statement is incorrect among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze the First Statement**:
- The first statement claims that the charge-to-mass ratio for canal rays is maximum for hydrogen ions.
- **Explanation**: A hydrogen ion (H⁺) has a charge of +1 and a very small mass (essentially the mass of a proton). This results in a high charge-to-mass ratio. Therefore, this statement is correct.

2. **Analyze the Second Statement**:
- The second statement states that the charge-to-mass ratio for cathode rays is independent of the gas taken.
- **Explanation**: The charge-to-mass ratio for cathode rays does not depend on the type of gas used in the cathode. It is a property of the electrons themselves, which are the primary constituents of cathode rays. Thus, this statement is also correct.

3. **Analyze the Third Statement**:
- The third statement claims that the nature of canal rays is dependent on the electrode material.
- **Explanation**: The nature of canal rays is primarily dependent on the type of gas that is ionized and not on the electrode material. Therefore, this statement is incorrect.

4. **Analyze the Fourth Statement**:
- The fourth statement is not provided in the transcript, but we can assume it is another statement regarding canal rays or cathode rays.
- **Conclusion**: Since we have already identified that the third statement is incorrect, we can conclude our analysis here.

### Final Answer:
The incorrect statement is the **third statement**: "The nature of canal rays is dependent on the electrode material."

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