A beam of ultraviolet light of all wavelengths passes through hydrogen gas at room temperature, in the x-direction. Assume that all photons emitted due to electron transitions inside the gas emerge in the y-direction. Let A and B denote the lights emerging from the gas in the x- and y-directions respectively.
(a) Some of the incident wavelengths will be absent in A.
(b) Only those wavelengths will be present in B which are absent in A.
(c) B will contain some visible light.
(d) B will contain some infrared light.
