Hi Friends! Please tell me if the question below is valid? "If the frequency of the source is changed from f to 2f ,keeping amplitude same,then total energy is changed by what amount?" What I conclude is"We can think it in two ways: 1 In classical sense,where I could not find any such relation. 2 In microscopic(quantum) sense E equals hf where h is Plank's constant .So it can give answer as E if the Energy at f is E.