Now, energy means this (Refer Slide Time: 16:19). But, actually, rho g is a constant. So, what we can do, we can plot E by rho g. But, E by rho g if I plot here, it is not going to give me a proper… See there is omega here. Now, here comes again the question. Supposing I break it down, this part to 100 components. This n is (Refer Slide Time: 16:53) 100. So, what happens, I get 100 points; half a square. But, if I have 200, I will get 200 points. If I add them all up, answer is different. So, what happens, what we do is that… Remember that last time we say about energy band; now, I take this frequency band.