Assertion: Like light radiation, thermal radiations are also electromagnetic radiation.
Reason: The thermal radiations require no medium for propagation.

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 question, we need to evaluate the assertion and reason given:

**Assertion:** Like light radiation, thermal radiations are also electromagnetic radiation.
**Reason:** The thermal radiations require no medium for propagation.

### Step-by-Step Solution:

1. **Understanding Electromagnetic Radiation:**
- Electromagnetic radiation includes a spectrum of waves such as radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. All these types of radiation do not require a medium to propagate; they can travel through a vacuum.

2. **Analyzing the Assertion:**
- The assertion states that thermal radiations are electromagnetic radiation, similar to light radiation.
- Thermal radiation primarily consists of infrared radiation, which is indeed a part of the electromagnetic spectrum. Therefore, the assertion is true.

3. **Analyzing the Reason:**
- The reason provided states that thermal radiations require no medium for propagation.
- This is also true, as thermal radiation can travel through a vacuum, just like light.

4. **Connecting Assertion and Reason:**
- Since both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion.
- The reason explains that thermal radiation, like light radiation, does not require a medium for propagation, which is a fundamental characteristic of electromagnetic radiation. Thus, the reason is indeed a correct explanation of the assertion.

5. **Conclusion:**
- Both the assertion and the reason are true, and the reason is the correct explanation of the assertion. Therefore, the correct answer is option A: both assertion and reason are true, and the reason is the correct explanation of the assertion.

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

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