This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
Frequency of woods lamp is ? 
Select and explain. 
A. 365 nm, B. 400 nm, C. 320 nm, D. 200 nm
A: 365 nm
Answer: A: 365 nm 
Explanation: Ans. is `a' i.e., 360 nm Wood's lamp Wood's lamp has an ultraviolet light lamp (365 nm) with a filter containing nickle oxide and barium silicate. The UV light, when absorbed by ceain substances, fluorescences in dark and the color of fluorescence is useful in diagnosis of the condition. Condition Fluorescent colours Tinea capitis Bright yellow green Erythrasma Coral red or pink Vitiligo Milky white Albinism Blue white Leprosy Blue white Tuberous sclerosis Blue white Pseudomonas infection Greenish white Porphyria Pinklorange Tinea versicolor Golden yellow