Assertion The frequency of the electromagnetic wave naturally equals equals the frequency of oscillations of the charge.
Reason The energy associated with the propagating wave comes at the expense of the energy of the source.

Options

A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not correct explanation of Assertion.
C. If Assertion is true but Reason is false.
D. If Assertion is false but Reason is true.

Explanation

To solve the assertion and reason question, we will analyze both statements step by step.

### Step 1: Analyze the Assertion
The assertion states that "the frequency of the electromagnetic wave naturally equals the frequency of oscillations of the charge."

- **Explanation**: When a charged particle oscillates (like an electron in an antenna), it creates changing electric and magnetic fields. These changing fields propagate through space as electromagnetic waves. The frequency of these waves is determined by how fast the charge oscillates. Therefore, the assertion is true.

### Step 2: Analyze the Reason
The reason states that "the energy associated with the propagating wave comes at the expense of the energy of the source."

- **Explanation**: When an electromagnetic wave is generated, it indeed takes energy from the oscillating charge (the source). The energy of the wave is derived from the energy of the charge's oscillation. Thus, this statement is also true.

### Step 3: Determine the Relationship Between Assertion and Reason
Now we need to evaluate if the reason correctly explains the assertion.

- **Explanation**: While both statements are true, the reason does not directly explain why the frequency of the electromagnetic wave equals the frequency of the oscillating charge. The assertion is about the relationship of frequency, while the reason discusses energy transfer. Therefore, the reason does not provide a correct explanation for the assertion.

### Conclusion
Based on the analysis:
- The assertion is true.
- The reason is true, but it does not correctly explain the assertion.

Thus, the correct answer is that both statements are true, but the reason is not a correct explanation of the assertion.

### Final Answer
The correct option is B: Both the assertion and reason are true, but the reason does not correctly explain the assertion.

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