# How Does the Length of a Wire Affect Resistance in a Circuit?

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• Published : April 29, 2012

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How Does The Legnth Of A Wire Affect Resistance In A Circuit? Physics Investigation

Aim:
To measure how the length of a wire affects the amount of resistance when an electrical current is passed through it. Background Information:
What is an electrical current
When a full circuit is created (i.e. a continuous loop has been made connecting the negative end of an electrical source to the positive) it creates a path for electrons to pass through. These electrons need a "push" factor to make them move. This push is called the Voltage. Once the electrons are moving this "flow" factor is called the Current and can be measured by the uppercase letter "I" or the symbol "A" (Amps). PotentialDifference

Resistance= Current

In my investigation we were finding out how resistance is affected by the legnth of a wire. For this we needed potential difference and current. When electrons move through a resistor they collide nwith stationery particles in the resistor. These collisions cause the resistor to heat up this can therefore change it's resistence. There are many different kind of resistors an example of this is (LDR, THERMISTER).

LDR (Light-dependent Resistor)
An LDR changes it's resistance depending on how much light there is eg: In Bright light the resistance falls
In darkness, the resistence is highest

Thermistor( Tenperature-Dependent Resistor)
A thermistor is similar to an LDR but it's resistance depends on temperature eg: In hot conditions the resistance drops
In cool conditions the resistance goes up

There are some factors that affect the resistance:

Legnth Of Wire: The longer the wire is, then larger it's structure is meaning more positive ions, therefore creating more collisions between positive metal Ions and free vibrating electrons which creates more resistance....