Skip to 0 minutes and 1 second In this video, we’re going to look at electric fields.
Skip to 0 minutes and 9 seconds We can draw the electric field lines around charge to investigate the overall behaviour of systems. By convention, we say that electric field lines go from positive to negative. So what this means is that the electric field lines radiate outwards from positive charge and inwards towards negative charge. So here’s my positive charge, and you can see that our field lines will radiate outwards. And here’s my negative charge, with those field lines radiating inwards.
Skip to 0 minutes and 43 seconds This convention means we can draw the electric field lines between charges. At the edges, the electric fields, or as we saw before, for the single charge. So here’s my positive and negative charges, and I’ve split the area. So on the outsides we can see that the electric fields are radiating away from the positive charge, and inwards towards the negative charge. In the centre is where it gets interesting. This is the region where the electric fields interact. So let’s look at the centre line, and we can say that that field line will go from positive to negative. But then we can see that we can’t just have a straight line for the rest of it.
Skip to 1 minute and 23 seconds We start to get this arcing outwards as the field lines merge together. That’s the overall shape of a positive and the negative charge interacting.
In this video, Leah introduces the idea of electric fields. You’ve already seen that charges will feel an electrical force from other charges. Electric fields are a slightly more abstract idea that is related to those forces. Essentially, the electric field tells us the direction of the force around a charge. It can also give us some idea of the size of that force - whether it is a large force or a small one.