A beam of ultraviolet light of all wavelength 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.
(i) Some of the incident wavelengths will be absent in A
(ii) Only those wavelengths will be present in B which are absent in A
(iii) B will contain some visible light
(iv) B will contain some infrared light