Investigate factors that affect resistance

Investigate factors that affect resistance

Introduction

During recent physics lessons, we have been studying resistance and

what factors may affect resistance. So far, we have learnt thatÂ…

à Resistance is the opposition to the flow of electrical current

à It is caused by electrons colliding with the atoms in a metal

à The more collisions there are, the greater the resistance will be

à When electrons collide with atoms, the atoms absorb the kinetic

energy from the electrons and vibrate faster

à This means the atoms and therefore the material is getting hotter

à The increased vibrations of the atoms make it harder for the

electrons to get past and therefore the resistance is increased

à Resistance is the ratio of voltage divided by current

à Ohm’s Law states that for a metallic conductor the current through

the wire is directly proportional to the voltage across its ends as

long as the temperature remains constant

We are now going to investigate further into what factors affect

resistance and how they affect it.

Variables

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The variables that I could use in my investigation areÂ…

à Atomic structure of the metal (type of metal)

à Temperature

à Length of the wire

à Thickness of the wire

These are all factors that would affect resistance, but I am only

going to investigate one factor.

Chosen variable

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The variable that I have chosen to use in this investigation is the

length of the wire. I have chosen to use this variable as it would be

the easiest to do as the length of wire is easy to measure and would

probably give the most accurate results due to this. I have chosen not

to change th type eof metal as this cannot be measured and would

therefore be harder to analyse. It would also be more difficult to

measure the thickness of the metal accurately with the equipment

available. Changing the temperature of the wire would be hard to