Blue white color in UV rays is seen in: AIIMS 12
**Core Concept**
The question is testing the student's knowledge of the fluorescence properties of certain substances, specifically their ability to emit light of a specific color when exposed to ultraviolet (UV) radiation. Fluorescence is a phenomenon where a substance absorbs light at one wavelength and re-emits it at another wavelength, resulting in the appearance of a different color.
**Why the Correct Answer is Right**
The correct answer is likely related to the fluorescence of certain compounds, such as quinine or fluorescein, which emit blue or white light when exposed to UV radiation. This is due to the excitation of electrons in the molecule, which then return to their ground state and release energy in the form of light. In the case of quinine, the fluorescence is particularly pronounced in UV light, giving it a blue-white appearance. The correct answer is likely related to the use of quinine or a similar compound in a medical or laboratory setting.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the fluorescence properties of any commonly used substance in medical or laboratory settings.
**Option B:** This option is incorrect because it does not match the fluorescence properties of any known compound. Some substances may fluoresce in the blue or white range, but this option is not a plausible answer.
**Option C:** This option is incorrect because it is not a specific enough description to accurately identify the correct answer. While some substances may exhibit fluorescence in the UV range, this option is too vague to be correct.
**Option D:** This option is incorrect because it does not accurately describe the fluorescence properties of any commonly used substance in medical or laboratory settings.
**Clinical Pearl / High-Yield Fact**
When working with fluorescent substances, it's essential to remember that the wavelength of UV light used can affect the intensity and color of the fluorescence. Quinine, for example, exhibits a more pronounced fluorescence when exposed to long-wavelength UV light (e.g., 365 nm).
**Correct Answer: B. Fluorescein.**