Resistance of a Wire

In this practical assessment we are going investigate how the length of wire affects the resistance of the wire.

First of all we need to get some general knowledge about the terms involved in this investigation. The main term is Power which is the amount of work done or energy transferred per unit of time. Electrical power generation is the process of converting any form of energy to electrical energy in any way possible for instance:

* Power station

* Nuclear power

* Wave power

* Wind power

* Tidal power

* Hydropower

* Geothermal power

Power (p) in physics is the amount of work done per unit of time. The scientific unit of power is the watt which is equal to one joule per second. Non-scientific units of power include horsepower (hp) or foot-pounds per minute. One unit of horsepower is equivalent to about 746 watts.

The next term is Current which in electricity refers to the electric current, the flow of electric charge. Lightning is an example of this electric current but probably the most familiar form of electric current is the flow of conduction electrons in a metallic wire. In electronics, electric current is most often the flow of electrons through conductors and devices such as resistors, but it is also the flow of irons inside a battery.

Ohm's law predicts the current in an ideal resistor to be the sum of applied voltage over electrical resistance:

V

R

Every electric current produces a magnetic field. The magnetic field can be visualized as a pattern of circular field lines surrounding the wire.

The final term is Resistance which is the opposing flow of an electrical current. The quantity of resistance in an electric circuit determines the amount of current flowing in the circuit for any given voltage applied to the circuit.