# Investigating How the Length of a Wire Affects Its Resistance

Investigating How the Length of a Wire Affects Its Resistance

In this investigation I will investigate how changing the length ofwire affects its resistance.Apparatus
Lengths of nickel chrome wire
Voltmeter x 1
Ammeter x 1
Electrical wires x 8
Variable resistor x 1
Power pack x 1
Beaker of water x 1
Hypothesis I think that the resistance will increase as the length of the wire increases because the distance that the electrons have to travel through the wire is greater. I also predict the resistance will increase in proportion to the length of the wire, because a wire (which acts like a resistor), is an Ohmic conductor. I also predict that the resistance is directly proportional to the voltage and current in a length of wire. The direct proportionality would be shown on the graph by a straight line. I also predict that if the length of the wire doubles, then the resistance will double. I predict that if you double the length of when, the resistance will double because as the length of wire increases there are more atoms of wire for the electrons to collide with. When the electrons collide with the atoms in the wire, they lose some of their charge. Also when they collide, heat and friction is produced. This heat and friction is resistance. Variables
Length of wire
Line Callout 2 (No Border): These are both classed as voltage.Resistance
on variable resistor
[image]Voltage from power pack
Length of wire ? If the length of the wire changes then it will have an effect on the resistance of the wire. By increasing the length of the wire then the resistance increases. The resistance of the wire increases because as increase the length, you are increasing the amount of atoms present in the wire. This means that the electrons have to pass through more atoms, and each time an electron collides with one of these atoms, it loses some of their charge and hence increases resistance. Voltage ? By increasing the voltage supplied then you are increasing the electromotive force supplied to the electrons. This means that the electrons will move faster through the wire and resistance will decrease because the electrons are not losing as much charge when they collide with the atoms of the wire. Constants In this investigation I will keep the following factors constant:
Temperature of the wire
Cross sectional area of the wire
Substance of the wire