UV radiations absorbed by ozone layer are

Options

A. UV-C
B. UV-C and `50%` UV-B
C. UV-C and UV-B
D. All types.

Answer

To solve the question regarding which UV radiations are absorbed by the ozone layer, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Types of UV Radiation**:
- There are three types of UV radiation emitted by the sun: UVA, UVB, and UVC.
- Each type has different wavelengths and levels of harmfulness.

2. **Understand the Wavelengths**:
- UVA has the longest wavelength.
- UVB has a medium wavelength.
- UVC has the shortest wavelength and is the most harmful type.

3. **Role of the Ozone Layer**:
- The ozone layer acts as a protective shield around the Earth.
- It absorbs a significant portion of harmful UV radiation emitted by the sun.

4. **Absorption Characteristics**:
- UVC radiation is completely absorbed by the ozone layer and does not reach the Earth's surface.
- UVB radiation is partially absorbed; about 50% of UVB radiation reaches the Earth's surface.
- UVA radiation is not absorbed by the ozone layer and reaches the Earth's surface entirely.

5. **Conclusion**:
- Based on the absorption characteristics, the ozone layer absorbs UVC completely and partially absorbs UVB.
- Therefore, the correct answer to the question is: **UVC and 50% of UVB**.

### Final Answer:
The UV radiations absorbed by the ozone layer are **UVC and 50% of UVB**.

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