(A) : Sky wave is reflected by ionosphere
(R) : The reflected wave is out of phase of incident waveand reach the receiving antenna along with the direct wave from transmitting antenna causes in interference.

Options

A. Both 'A' and 'R' are true and 'R' is the correct explanation of 'A'.
B. Both 'A' and 'R' are true and 'R' is not the correct explanation of 'A'.
C. A' is true abd 'R' false
D. A' is false and 'R' is false

Answer

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

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Sky wave is reflected by ionosphere."
- This is a true statement because sky wave propagation involves radio waves being transmitted from an antenna, traveling through the atmosphere, and being reflected back to Earth by the ionosphere.

2. **Understanding the Reason**:
- The reason states that "The reflected wave is out of phase of the incident wave and reaches the receiving antenna along with the direct wave from the transmitting antenna, causing interference."
- This statement is also true. When a wave reflects off a surface (like the ionosphere), it undergoes a phase change. This means that the reflected wave is indeed out of phase with the incident wave.

3. **Analyzing the Relationship**:
- We need to determine if the reason correctly explains the assertion.
- Since the assertion is about the reflection of sky waves by the ionosphere, and the reason explains the phenomenon of phase change and interference that occurs as a result of this reflection, the reason does indeed provide a correct explanation for the assertion.

4. **Conclusion**:
- Both the assertion and the reason are true statements.
- The reason correctly explains the assertion.

### Final Answer:
Both the assertion (A) and the reason (R) are true, and the reason is the correct explanation of the assertion.

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