A galvanic sail is made up of two half sail that is two electrodes and as electricity flows in a galvanic sail that means there has to be certain difference in the electrode potential between them. Let me write that a galvanic sail is made up of two half sail that is two electrodes and some potential difference or electrode potential, some electrode potential difference is the current to flow. So I have written here obviously a galvanic sail has two electrodes and they have different electrode potential that causes the electrons to flow as a result of that electricity will flow over there. Now as they have two different electrode potential then obviously one of them must have higher value of electrode potential, another one must have lower value of electrode potential. The electrons move from one electrode from one electrode that is higher electrode potential to another electrode which have lower electrode potential. So as you can see over here one of the electrode must have higher value of electrode potential, another electrode must have lower value of electrode potential and the electrons move from higher value of electrode potential to the lower value of electrode potential. Now this difference in the potential causes the electrons to flow right. So the difference in the electrode potential causes the electrons to flow and that is called electro-motiv force. So it is defined as the force which causes the electrons to flow in a galvanic sail in a galvanic sail is called in a galvanic sail. So this is the definition of electro-motiv force. It can also be defined as the difference between the electrode potential of the two sail, the difference between the electrode potential of two sail is called EMF electro-motiv force. So you can divide EMF in any way you want which able you feel easy you can write that definition in your examination as well. Mathematically this is the electro-motiv force or overall potential of sail can be calculated by the formula E reduction minus E oxidation. So E reduction means the oxidation potential of reduction half or simply you can say cathode. Similarly E oxidation means the electrode potential of oxidation half or you can see a node. Now if you see a sail notation in sail notation let me write the sail notation of galvanic sail in which zinc converts to Z and 2 plus I am not writing some different information in the bracket, CO2 plus converts into CU. So this is how we write the sail notation of a denier sail. Now you can see over here this is the first half this is the second half and always remember the first half is for a node and the second half is for cathode or you can simply understand the first half is always for oxidation and the second half is always for the reduction. So here from the formula what do we see first of all it comes reduction den oxidation right. So you can simply write the formula E R minus E L R means right value L means left value ok. So you can use any formula between them whichever formula you want to use you can use that and you will get the value of oxidation potential of the sail. Now one more thing we need to understand over here is that the oxidation potential of overall sail depends on the oxidation potential of reduction half and oxidation half in individual state that means when the sail is not working then we need to find the value of E reduction and E oxidation by some method and if we find the value if the if we find the difference of their value then we get the value of potential of the overall sail that is a mathematical value and that is calculated by using a potentiometer. So this is what the electro motif force actually is. I hope you understood everything about electro motif force that is all in this video. If you like the video please share this video as much as you can and thank you for watching the video.