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How many of the following statements are...

How many of the following statements are correct ?
1. Good ozone is found in the stratosphere.
2. UV radiation having a lower wavelength than UV -B is almost completely absorbed by the Earth's atmosphere.
3. UV - B causes snow blindness and cataract.
4. dB is a unit to measure the thickness of ozone.

A

one

B

Two

C

Three

D

Four

Text Solution

AI Generated Solution

The correct Answer is:
To determine how many of the statements are correct, we will analyze each statement one by one: 1. **Statement 1: Good ozone is found in the stratosphere.** - This statement is **correct**. The ozone layer, which contains "good" ozone, is located in the stratosphere. It plays a crucial role in absorbing harmful ultraviolet (UV) radiation from the sun, thus protecting life on Earth. 2. **Statement 2: UV radiation having a lower wavelength than UV-B is almost completely absorbed by the Earth's atmosphere.** - This statement is also **correct**. UV radiation with shorter wavelengths than UV-B, such as UV-C, is indeed absorbed by the Earth's atmosphere, primarily by the ozone layer, preventing it from reaching the surface. 3. **Statement 3: UV-B causes snow blindness and cataract.** - This statement is **correct**. UV-B radiation is known to cause various health issues, including snow blindness (a temporary loss of vision due to UV exposure) and cataracts (clouding of the lens in the eye). 4. **Statement 4: dB is a unit to measure the thickness of ozone.** - This statement is **incorrect**. The unit used to measure the thickness of ozone is the Dobson unit (DU), not decibels (dB). Decibels are a unit of sound intensity, not related to ozone measurement. Now, let's summarize the correctness of each statement: - Statement 1: Correct - Statement 2: Correct - Statement 3: Correct - Statement 4: Incorrect **Conclusion:** Out of the four statements, three are correct and one is incorrect. **Final Answer: 3 statements are correct.** ---
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