(A) : Propagation of electromagnetic waves as microwaves is better than that as sky waves.
(R) : Microwaves have frequencies 100 GHz to 300 GHz with very good directional properties.

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 the assertion (A) and the reason (R) provided.

### Step 1: Understand the Assertion
The assertion states that "Propagation of electromagnetic waves as microwaves is better than that as sky waves."
- **Explanation**: This means that microwaves can travel more effectively than sky waves (which are typically radio waves).

### Step 2: Evaluate the Assertion
To determine if the assertion is true, we need to consider the properties of microwaves and sky waves.
- **Microwaves** have higher frequencies (ranging from 100 GHz to 300 GHz) compared to sky waves (radio waves). Higher frequency waves generally have better propagation characteristics, especially in terms of penetration through obstacles.

### Step 3: Understand the Reason
The reason states that "Microwaves have frequencies 100 GHz to 300 GHz with very good directional properties."
- **Explanation**: This indicates that microwaves not only have a higher frequency but also possess good directional properties, meaning they can travel in a straight line without bending around obstacles.

### Step 4: Evaluate the Reason
To determine if the reason is true, we need to confirm the frequency range of microwaves and their directional properties.
- **True**: Microwaves indeed have frequencies in the range of 100 GHz to 300 GHz, and they exhibit very good directional properties. This means they can be focused into narrow beams, which is advantageous for communication.

### Step 5: Conclusion
Both the assertion and the reason are true. Furthermore, the reason correctly explains why the assertion is true. Therefore, the correct answer is that both A and R are true, and R is the correct explanation of A.

### Final Answer
Both A and R are true, and R is the correct explanation of A.

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