Wood's lamp is made up of -: (A) 9% nickel oxide with 6% barium silicate, (B) 9% nickel oxide with 9% barium silicate, (C) 6% nickel oxide with 6% barium silicate, (D) 9% nickel oxide with barium silicate
Answer is D. Wood's Lamp It is a low intensity ultraviolet light(360nm) emitted by a high pressure mercury lamp fitted with a special filter made up of 9% nickel oxide and silica.