# Resistance Investigation. My aim in this investigation is to measure the amount of resistance in the different lengths of the wire.

Physics coursework:

Atom resistance

Aim: My aim in this investigation is to measure the amount of resistance in the different lengths of the wire. I will measure the different amounts of resistance by using the Ohms which is that the current =voltage / resistance:

Prediction: My prediction was that the volt readings would remain similar measured using the voltmeter and the current would increase as the length of the wire would, thus increasing the amount of resistance in the increasing lengths of the wire.

Resistance

The current in a circuit can be changed according to the amount of voltage that is used to power the circuit. Another factor that is important is the amount of resistance that can affect the size of the current in the circuit. The resistance of an atom or an electron is when the flow of the electron in a circuit is altered or is being controlled from the loss of energy when the electron collides with the atoms in the path of the electron’s circuit. When the voltage of the battery or any other source of the power in a circuit pushes the electrons, the electrons then in the circuit collide with by passing electrons and also the other atoms, therefore the energy that electrons carry is transferred to the atoms and the other electrons that the collision occurs with gain the energy. The thermal energy from the heat of the collision is converted into kinetic energy which the atoms use to move and also collide with more electrons to increase the resistance.

What effects Resistance?

There are many variables that affect the flow of electrons in a current and the resistance of the electrons. One of them is the cross-sectional area of the wire because as there may be more space for the electrons to travel through the wire so the resistance of the electrons will be decreased as the flow of the current in the circuit is sped up. However if the cross-sectional area of the wire causes the flow of the current of the electrons to retard then the resistance of the flow of electrons would increase as the electrons have less space to travel through. Another variable that could affect the resistance is the material that the wire consists of. If the wire is made of a single element then the electrons moving through the atoms will only be able to collide with the atoms of that element which would increase the flow of the current and decrease the resistance of the electrons. However if the material of the wire is and alloy then the resistant of the electrons would certainly increase, as the second metal contaminating the first metal would allow more contact between the electrons and the atoms of the first and the second element, which increase the resistance and decrease the flow of the current. Also the third variable that can affect the resistance of the electrons is the temperature of the wire and the conditions around it. As temperature of the wire rises the resistance can increase because the atoms would be in faster motion because the thermal energy can be converted into kinetic energy which will decrease the flow of the current and will increase the resistance of the current because more collisions will occur.

What variables can I investigate?

One of the many variables that I can investigate is the length of the wire. The length of the wire means that if the wire is longer then the amount of resistance is increased because the electrons that travel through the wire would have to collide with more atoms. This would decrease the flow of the current. This would be an appropriate variable to consider to investigate in the investigation of the amount of resistance because the length of the wire can be measured easily in centimetres and also the amount energy left after a long wire can be tested to see if the flow of the current has been decreased or not. Also another variable that I could test is the temperature of the wire and the amount of resistance increased because the temperature that would increase could convert the thermal energy into kinetic energy for the atoms to vibrate more and then there would be more collisions which would decrease the flow of the current. This would be a suitable variable to investigate because the temperature will be measured in co in a room with controlled conditions (room temperature). The apparatus would be a thermometer and a Bunsen burner to use to heat the wire. Problems that could occur could be that the environmental conditions could not be suitable for the investigations.

Apparatus list:

• Ammeter: Is used to measure the amount current flow through the conductor that is used (nickel chrome).
• Voltmeter: The voltmeter is used to measure the amount of volts that the wire (conductor) contains.
• Amp: The amp is used to power the circuit with electricity (2V is recommended).
• Red and black wires: Used to connect the voltmeter, ammeter, amp and test piece to create a circuit.
• Crocodile clips: These are used to clip the wires to the test piece (conductor).
• Ruler: To measure the length of the wires (conductors) that will be used.
• Pliers: These are used ...