 I am trying to find out the potential due to a spherical charge which is distributed in the volume. So you have a solid sphere, this is a non-metallic sphere and charges are uniformly distributed in the volume. A little charge in states is low, spherical is distributed, so it has shells of different radius. So everything depends on the point charge, the point is outside, this point is outside, that small area is different than that. So potential will be a bigger, smaller. In this case, the concept and that can be that I have used this basic concept and called this a concept. That much charge is outside. So you can tell me how much is that. Inside a hollow sphere, the potential you can imagine over here. The shell lets you dequeue the charge divided by 6 is not common inside the volume charge distribution in a sphere. Sir, can you not do it now? It has to be by outside and not to be able to go into the volume of that. You are finding a particular point, which distance will it take? The point will be different. Into Q is a very simple thing. In physics at least. Because in physics if you start thinking randomly, there is no limit, limit up to which you can take nonsense. It is not in your NCID cell. So let's talk about it, the concept of how you can explore the potential in the front side. As we move in the direction, we need to keep in mind when we talk about when the graph comes in. Concentric, spherical shape. More than one might be. Let's see how it is. No doubt. Keep charging up. Keep charging. Outside there will be air. You could neutralize this. You have seen the lightning. If you touch it, your potential becomes similar to the same if you touch the high potential. Don't try it. I am not retarded. Sir, this is a few million. Just touch it also. So you will not die. But then here. So they will be for each other. And in the portion only. Stand up, because there is a portion between the head and the charge. Charge is low, right? Charge is low. In your chapter, that was... Sir, how can you do the one thing? This can be easily charged. But how can you do the one thing? You can keep the generating whatever you want. A steel wire. Steel mesh. That is rubbing against the rail. You can. I mean, you worry about that that brush will get charged itself. That you can just once in a while... I mean, if it is a gross system. Then not possible. Sir, is it... But let's not discuss on it. If you keep the wire kind of, the lower brush kind of ground, right? So that the lower brush... So that the lower brush itself doesn't get charged. If it gets charged, then it will become more different. See, the thing is the brush becomes negative charged. Then it becomes more and more negative charged. This negative charge is not itself. Although... But you have to once in a while... Until the rest of the time... So, let's do a bit. One small measure, okay? The charge per unit length lambda. Total length is potential at this point. This point is at a distance of L by 10. From one end. Okay? Ah, correct, correct, correct. This small charge...