Resistance and Length of a Wire

Resistance and Length of a Wire

I will test different lengths and areas of wire and observe and record

the resistance. I will see how these variables affect resistance,

which length or area of wire gives the least resistance and which

gives the most. In my preliminary experiment I will vary the length of

the wire I use. By varying the length I

Scientific knowledge

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. e.g. The

filament across an electric bulb is quite thin as needs to resist the

flow of particles for the bulb to glow. The greater the resistance the

more voltage is needed to push a current thorough a wire

Resistance occurs when the electrons travelling along the wire collide

with the atoms of the wire. These collisions slow down the flow of

electrons, causing resistance. Resistance is a measure of how hard it

is to move the electrons through the wire.

Resistance is measured in Ohms. Ohms law states that the current

flowing through a metal wire is proportional the potential difference

across it providing the temperature remains constant.

Ohms law, (V=I/R). This means that for a certain current there will be

a greater voltage across the wire if it has more resistance.

Therefore voltage measures the amount of energy used up in getting

each coulomb of charge through a wire. The units for voltage are the

same as joules per coulomb.

A metal wire can conduct electricity because the outer electrons of

the atom are free to carry a charge. An electron is part of an atom

with a negative charge and almost no mass. The more free electrons a

metal has the better conductor it is.

Predictions

Resistance/Length

I think that as the length of Nichrome wire increases so will the

resistance.