Assertion: A direct current flows through a metallic rod, produce magnetic field only outside the rod.
Reason: There is no flow of charge carriers inside the rod.

Options

A. If both the assertion and reason are true and reason is a true explantion of the assertion.
B. If both the assertion and reason are true but the reason is not true the correct explantion of the assertion.
C. If the assertion is true but reason false
D. If both the assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understanding the Assertion
The assertion states that "A direct current flows through a metallic rod, produce magnetic field only outside the rod."

- A direct current (DC) flowing through a conductor generates a magnetic field around it. According to Ampère's circuital law, the magnetic field is produced in the space surrounding the conductor. However, it is important to note that the magnetic field is not limited to just the outside of the rod; it also exists inside the rod.

### Step 2: Understanding the Reason
The reason states that "There is no flow of charge carriers inside the rod."

- This statement is incorrect. When a direct current flows through a metallic rod, charge carriers (typically electrons) do move through the entire volume of the rod. Therefore, there is indeed a flow of charge carriers inside the rod, which contributes to the magnetic field.

### Step 3: Conclusion
Since both the assertion and the reason are incorrect, we can conclude that:

- **Assertion**: False (the magnetic field exists both inside and outside the rod).
- **Reason**: False (there is a flow of charge carriers inside the rod).

### Final Answer
Both the assertion and the reason are false.

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