A : Electrons flow in external circuit of galvanoic cell while ions flow in internal circuit.
R : Direction of current flow is reverse that of electron flow.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4).

Answer

To solve the question regarding the assertion and reason related to a galvanic cell, we can break it down into clear steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Electrons flow in the external circuit of a galvanic cell while ions flow in the internal circuit."
- In a galvanic cell, oxidation occurs at the anode (where electrons are released), and reduction occurs at the cathode (where electrons are accepted). The electrons travel through the external circuit from the anode to the cathode, while ions move through the internal circuit.

2. **Understanding the Reason**:
- The reason states that "The direction of current flow is reverse that of electron flow."
- By convention, electric current is defined as the flow of positive charge. Therefore, the current flows from the positive terminal (cathode) to the negative terminal (anode), which is opposite to the flow of electrons (which move from anode to cathode).

3. **Analyzing the Statements**:
- Both the assertion and the reason are correct statements.
- The assertion accurately describes the flow of electrons and ions in a galvanic cell.
- The reason correctly explains the relationship between current flow and electron flow.

4. **Determining the Relationship**:
- While both statements are true, the reason does not directly explain the assertion. The assertion is about the flow of electrons and ions, while the reason discusses the direction of current flow, which is a separate concept.

5. **Conclusion**:
- Since both statements are true but the reason does not serve as the correct explanation for the assertion, we conclude that the correct answer is:
- **Both assertion and reason are true, but the reason is not the correct explanation for the assertion.**

### Final Answer:
The correct option is: Both assertion and reason are true, but the reason is not the correct explanation for the assertion.

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