Identify the wrong statements with reference to UV rays

Options

A. UV-A is more harmful to animals than UV-B
B. UV radiations falls in the range between 100 -300 nm wavelength
C. UV radiations is classified into three categories
D. UV radiations kills microorganisms.

Answer

To identify the wrong statements with reference to UV rays, we will analyze each statement provided in the question. Here’s the step-by-step breakdown:

### Step 1: Analyze the Statement about UVA and UVB
- **Statement**: "UVA is more harmful to animals than UVB."
- **Analysis**: This statement is incorrect. UVB rays are actually more harmful than UVA rays when it comes to causing skin damage and skin cancer. UVB rays are responsible for sunburn and have a more significant role in the development of skin cancer.

### Step 2: Check the Wavelength Range of UV Radiation
- **Statement**: "UV radiations fall in the range between 100 to 300 nanometer wavelength."
- **Analysis**: This statement is partially correct but misleading. The UV spectrum actually ranges from about 100 to 400 nanometers. The specific ranges are:
- UVA: 315 to 400 nm
- UVB: 280 to 315 nm
- UVC: 100 to 280 nm
Therefore, stating that UV radiations fall only between 100 to 300 nm is incorrect as it excludes the UVA range.

### Step 3: Classification of UV Radiation
- **Statement**: "UV radiation is classified into three categories."
- **Analysis**: This statement is correct. UV radiation is indeed classified into three categories: UVA, UVB, and UVC.

### Step 4: Effect of UV Radiation on Microorganisms
- **Statement**: "UV radiations kill the microorganisms."
- **Analysis**: This statement is correct. UV radiation, particularly UVC, is known to kill microorganisms by damaging their DNA.

### Conclusion
After analyzing all the statements, we find that the wrong statements are:
1. "UVA is more harmful to animals than UVB." (This is incorrect; UVB is more harmful.)
2. "UV radiations fall in the range between 100 to 300 nanometer wavelength." (This is misleading; the correct range is 100 to 400 nm.)

### Final Answer
The wrong statements with reference to UV rays are:
1. UVA is more harmful to animals than UVB.
2. UV radiations fall in the range between 100 to 300 nanometer wavelength.

---