Wavelength of UVB is :: (A) 250-280 nm, (B) 280-320 nm, (C) 320-400 nm, (D) 400-700 nm
Answer is B. Ans. B. 280-320 nmThe wavelength found most effective in treating skin disease with phototherapy is UVB with warden gfh of 311 (+- 2nm) (narrow band UVB, NBUVB).The wavelengths between 4(N and 7AO nm are visible to the human eye.