Wednesday, March 20, 2019

Physics :: essays research papers

Electricity has three features that include contemporary, electric potential and protection. ongoing is the flow of electrons round a circuit that is measured by the ammeter in amps (A). Whilst the emf, refer to as potential difference, is the driving force that circulates the sure or so the circuit that acts like an electrical pressure. The unit of measurement for this is Volts (V), which is measured by a voltmeter. Resistance is a force that slows down the current consequently it slows down the flow of current. This is measured in Ohms (W). Between the voltage and resistance on that point is equilibrium, where the voltage impels the current, whereas the resistance is opposing this electrical pressure. The relative sizes of the voltage and resistance decide how big the current will be. Increasing the voltage allows more current to flow, whilst increasing the resistance would decrease the amount of current flowing round the circuit. Discovered by George Ohm in 1826, the cur rent is in direct relative amounts to the potential difference. If the temperature is kept constant as sanitary as other conditions, Ohms law is obeyed. The graph on the side illustrates the current through a resistor is proportional to the voltage. V=IR gives the facial expression for Ohms law. In order for current to flow it requires electrons to carry the electric current. The electrons ar the negative charge that can freely move about. Within metals there be a sea of electrons that can carry the electric current, which is causa why they conduct so well and are used for numerous another(prenominal) purposes, such as telegraphs. Factors During the investigation there will be many factors that will affect the resistance in a wire. These factors include length of wire If the wire length increases, the maintain for the electrons to pass through would trail a longer period of time since the electrons collide more with atoms of the wire. As a result there is an increase in r esistance as the number of collisions cause the electrons to flow slowly, which justifies the term for resistance. Conversely if the length of the wire is shortened, the time taken for electrons to travel is reduced given that there are not as many electrons colliding with atoms. As results there are a small number of collisions, hence reduces the resistance. Thickness of wire - A wider extensiveness of the wire causes atoms within the wire to expand a small distance between each other.