Investigation into the factors which affect the resistance of a wire.

Authors Avatar

        -  -

Investigation into the factors which affect the resistance of a wire.

Aim:

To investigate how the resistance of a wire is affected by the length of the wire.

Introduction:

In this investigation, I will find out the relationship between the length of wire and the resistance across it, according to the formula V=I x R. In Ohm’s Law, resistance can be calculated by dividing the voltage by the current. The investigation that is being carried out shows how the resistance (founded by Ohm and recorded in Ohm’s laws) is affected by lengths of a wire. Physists believe in two main theories: the longer the wire the more the resistance, the thinner the wire the more resistance.

I will be investigating the first of the two theories and justify my hypothesis.  

Hypothesis:                                                                                                                                                         The longer the wire in the circuit, the higher the resistance will be.

Justification of hypotheses:

I have based my hypothesis on many sources, such as internet based websites and books. Each source states that the longer the wire the more the resistance. This is mainly due to the electron movement. Simply, the electrons in the circuit create the current. These are the particles that move through a circuit. However, every wire has some resistance that is already present. In the copper wire that I am investigating on, the resistance is the copper ions. These ions are positively charged and so attract the negatively charged electrons. These ions do not move, but create a “barrier” for the moving electrons. As the electrons move, there is more chance there is that they will collide with an ion and therefore the electron loses energy (as it collides).  If the wire is longer, the more ions are present and therefore the more chances that the electrons will collide with the ions. This will then cause less energy to be sent along.

How the resistance in measured:

The resistance is expressed in Ohms, (Ω) following the Ohm’ Law.

        Ohm's Law defines the relationships between (V) voltage, (I) current, and (R) resistance. One ohm is the resistance value through which one volt will maintain a current of one ampere.   (http://www.the12volt.com/ohm/ohmslaw.asp)  

                                                                                       

Where I is current in amps and V is the applied voltage in volts.

The equation of Ohm’s Law is:                                                                                                                                           _                                        V = IR

Join now!

       

Where I is current in amps, V is the applied voltage in volts, and R is resistance in ohm 

Key terms:                                                                                                                                                   ...

This is a preview of the whole essay