Coursework.biz - The UK's Essay Exchange Site

Earn £1 everytime your essay is downloaded

What affects the resistance of a piece of wire?

GCSE: Physics

Title:  What affects the resistance of a piece of wire?
Description  I am going to investigate “What affects the resistance of a piece of wire?” Resistance is a force which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. The circuit itself can resist the flow of particles if the wires are either very thin or very long.
Word Count:  1400


This is only a preview of the full essay

Buy the FULL essay for £1.95 now!* - Existing members please login


Preview:

...
There are three main factors which affect the resistance of a wire:

 The length of the wire
 The thickness of the wire (The diameter of the wire)
 The temperature of the wire

The effect these factors have:

1. The length of the wire: - if a wire is longer, the moving electrons have further to go, so there is a more chance of an electron colliding with an atom. Increasing the length of a wire increases its resistance.

2. The thickness of the wire: - the moving electrons in a current are spread out over a greater area. There is less chance of an electron colliding with an atom, so more current can flow. Increasing the thickness of a wire decreases its resistance.

3. The temperature of the wire: - if the wires temperature is higher, its atoms vibrate more, each one moving around a fixed centre. There is more chance of electrons colliding with the vibrating atoms, so less current can flow. An increase in temperature increases the resistance of a wire.

I will investigate the length of the wire and see if it will affect the resistance.
I predict that as the length of wire becomes longer the resistance will become gradually bigger. I also predict that the longer the wire the less current will flow which increases the resistance. This is because electric current is the movement of electrons through a conductor, so when resistance is high conductivity is low. Therefore the electrons will have to push their way through a shorter path of atoms in the wire, reducing their resistance. Whereas, if the length was longer, then the number of atoms in the wire increase.

A piece of wire is made up of hundreds of atoms. An electrical flow is able to run through the wire, these are electrons. As the current increases the velocity of the electrons increases which increases the amount of collisions between the electrons and the atoms. This creates a higher resistance.

I think that there will be more resistance on a longer piece of wire, the longer wire, the higher the resistance. This will happen because of the amount of particles inside the wire that the flow of electrons will need to pass. In turn, there will be more collisions between the electrons and the atoms inside the wire. This is the resistance. A higher the resistance will mean more collisions.

In a wire, the atoms are held very close together because it is a solid. The atoms are made up from neutrons, protons and electrons. In a along piece of wire (opposed to a shorter piece) there are more atoms so there is less room for the electrons to get through. This will result in the electrons losing some of their energy as they bump into the atoms. This means that it is more difficult for the electrons to pass through the wire. In a shorter piece of wire, there are fewer atoms so it is easier for the electrons to travel through the wire. These are both examples of resistance.
...

Buy the FULL essay for £1.95 now!* - Existing members please login


*Very simple registration required first

 

--------

© Copyright Oxford Information Services Ltd 2004-2010

Bad Request (Invalid Hostname)