in this video we're going to look at the generator effect which is also known as electromagnetic induction to do this let's imagine we have two magnets with a magnetic field between them if we now take a piece of wire that's been bent into a coil shape and move it through the magnetic field it will induce a potential difference in the wire which you can see by the plus and minus signs there are a couple of important things to notice here though one is that whenever the wire stops moving like it does whenever it reaches the top or the bottom then the potential difference disappears this is because it's the change in the magnetic field that the wire experiences as it moves through it that creates the potential difference so if the y is not moving then there won't be any potential difference because nothing's changing the other thing to notice is that the direction of the potential difference swaps each time we change the direction which is why the plus and minus signs keep switching around now at the moment we just have a piece of wire we don't have an actual circuit and so even though there's a potential difference it can't generate any current however if we joined the two ends together so that we had a complete circuit then the induced potential difference would generate a current because electrons would be able to flow around the circuit the same thing happens if we keep the wire still and instead move the magnets up and down this is because the wire is still experiencing a change in the magnetic field which remember is the key idea in electromagnetic induction if we instead move the wire back and forth like this though then this time there won't be any induced potential difference or current because the wire isn't actually experiencing a change in the magnetic field now if we wanted to change the size of the induced potential difference and therefore the current that it generates we can do three things one is to change the strength of the magnetic field for example if we used stronger magnets which produced a stronger magnetic field then would induce a larger potential difference the second is to move the wire or the magnets more quickly the faster they move the faster the magnetic field will change and so the bigger the potential difference will be the final change we can make is to shape the wire into a proper coil so that it has multiple turns and the more turns it has the bigger the induced potential difference will be so to summarize everything up to this point when a wire experiences a change in magnetic field a potential difference will be induced across the wire and if the ends of the wire are connected to make a closed circuit then a current will flow around the circuit in addition we can increase the strength of the induced current by increasing the strength of the magnetic field increasing the speed that the wires or magnets move at or by adding more turns to our coil the very last thing we discover is how this concept works when removing a single magnet into and out of a coil of wire just like before this movement of the magnetic field relative to the coil induces a potential difference in the coil and because the circuit's complete this generates a current also like before whenever we change the direction of the magnet it changes the direction of the current and we can also change the direction of the current by swapping the poles of the magnets like if we were to turn it around the other way anyway that's everything for this video so hope that all made sense and i'll see you again soon you