foreign but now let's talk about electrical fields now electrical fields are fields which are created by an electric charge a point charge is a charge created by a single point example a proton or an electron the properties of the point charge are that it is Radio filled is stronger closer towards the point charge it is made up of monopoles and the arrows point away for a positive charge or the arrows point inwards for a negative charge the electric field strength is equal to KQ divided by R square where e is the strength of the electric field K is the coulomb constant Q is the charge of the point charge and R is the distance from the charge [Music] oppositely charged particles create an attractive Force for each other like charged particles create a repulsive Force against each other you do need to know to remember how to draw this now the formula here is very similar to that of the gravitational potential energy so instead of G uh a capital m g so instead of using this formula foreign so it's actually very similar to one another where in this case f stands for the force on the charge K stands for the coulomb constant q1 stands for charge of the first point charge Q2 stands for the charge of the second Point charge and R is the distance between the centers of the two charges now notice the diagrams in the diagram there is nothing in between the negative charges the reason for that is because we said that field lines are vectors therefore they would cancel each other out in the middle second of all let's talk about kq1q2 divided by R square in this case we are referring to the fact that if we're looking at a proton and an electron an electron revolves around a proton right so we can use this formula to find the electric force which is being applied on the electron by the proton and obviously the the force that the electron applies on the proton foreign oppositely charged plates create a electric field and this is known as a dipole indicated by the evenly spaced parallel lines putting a charge particle in the field will cause it to move towards the oppositely charged particle and the work will be done on the particle the field that you see here is different from a radial field right foreign therefore we call this a uniform field where the electric field strength is voltage divided by distance force is equal to Q multiplied by E and work is charge multiplied by voltage where electric field strength is the strength of the external electric field V is the voltage D is the distance between the plates f is the force in Newton's Q is a charge of the POI charge and W is the work in joules so let's have a go on this question here an electron is placed between two electric plates which are placed 30 centimeters apart and have a potential difference of 20 volts what is the force acting on the electron [Music] uh foreign voltage is 20 it's 20 volts divided by a distance of 0.3 you can find the electric field strike let me write that again that looks awful okay [Music] foreign [Applause] acting here on the electron would be what we found here 66.7 multiplied by 1.6 times 10 to the power of negative 19. foreign