The transition from the state n = 4 to n = 3 in a hydrogen-like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition
(a) 21 (b) 32
(c) 42 (d) 54
(d) As the transition n = 4 and n = 3 , results in UV radiation and infrared radiation involves smaller amounts of energy UV. So we require a transition involving initial values of n greater than 4 e.g. 54.