• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4

Investigating the factors affecting the resistance if a wire.

Extracts from this document...

Introduction

Investigating the factors affecting the resistance if a wire

Possible factors

Material

The material that we use could affect the resistance of a wire because density of the material will affect the electron flow. However there are only three choices of material available and they are Copper, Constantan and Nichrome.

Thickness

With a thicker wire there will be more electrons, therefore there will be more to move around and consequently there will be less resistance. There is however only a limited range of thicknesses existent.

Shape

If the wire is straight, or if it is bent will affect the resistance. This cannot be done in equal steps and cannot be changed systematically.

Temperature

If the temperature is increased then it will effect the movement of the ions, as they will move around more frequently. The ions would have more energy and would vibrate more, therefore causing more collisions and more resistance. The temperature is quite difficult to control and so would be a very difficult investigation.

Length

If the wire is longer then the ions will have further to travel and more electrons will come into contact with the ions. The ions will lose more energy therefore there will be a greater resistance and less current around the circuit.

The variable that I have chosen to change for this investigation is length.

Middle

100cm        Constantan        28swg           0.15                0.70        4.7

These results show that Nichrome will be the most suitable material to use. This is because Nichrome is the material that has given me the widest range ofresults.

I now need to find a suitable diameter of Nichrome to use.

Material Length        Diameter         Current         Voltage Resistance

(Amperes)(Volts) (Ohms)

Nichrome 10cm        26swg                0.70         0.48          0.7

Nichrome 100cm        26swg                0.11         0.73          6.6

Nichrome 10cm        32swg                0.35         0.61          1.7

Nichrome 100cm        32swg                0.04         0.80          20

The diameter 32swg has given me the widest range of results. I am going to usethe material Nichrome and the diameter 32swg for my experiment.

Equipment

Power pack

6 wires

Ammeter

Resistor

Variable Resistor

Voltmeter

Metre rule

Clips

Method

·Firstly, using the equipment above, I will need to set up the circuit, as

shown below.

·Set the power pack to 2V.

·Connect one of the crocodile clips to 0 on the metre rule and connect the other at 10cm. Keep the slider on the variable resistor where it is. Read off the voltmeter and the ammeter and record results. Move the slider on the variable resistor along into position two. Read off the voltmeter and the ammeter and record results. Continue doing this until the slider has reached position 5 on the variable resistor and then repeat the process, only this time moving the crocodile clip up to 20cm, while the other remains at o. Continue up to 100cm.

Fair testing

Conclusion

Further work

As I have already proved that an increase of length means an increase in resistance I could investigate another variable.

I could investigate the variable of thickness. With a thicker wire there will be more electrons, therefore there will be more to move around and consequently less resistance.

Method

I would take the reading for the first thickness of the wire. Recording the current and voltage. This would enable me to discover the resistances.

Resistance = Voltage (Volts)

(Ohms)         Current (Amperes)

Next I would replace the wire with another wire of a different thickness. I would record the results as I had done in the previous experiment. I would probably take several readings to ensure my accuracy and I would use approximately 5 different thicknesses. I would then display my results in a line graph.

If given the time I could have extended the experiment on length. I could have investigated more of the lengths to see if the pattern continued, instead of stopping at 100cm.

There were not too many outrageously anomalous results and my prediction was correct. Overall I think that the investigation was a success.

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.

Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

Related GCSE Electricity and Magnetism essays

1. The factors affecting the resistance of a metalic conductor.

4 star(s)

a smaller cross sectional area and pass current through it via a parallel circuit, the resistance is slightly higher than when using a normal circuit. This is because placing resistors in parallel is equivalent to increasing the cross-sectional area A through which current can flow.

2. Factors Affecting the Efficiency of a Wind Turbine

They add unnecessary weight. Limitations Larger blades have a great swept area but they also have more torque. There is a limit to the length of the blade and this depends on the blowing wind. If the wind blowing is continuously and covers a very large area then long blades

1. To investigate the factors affecting current in a wire.

My second graph of length against resistance is a straight line through the origin. Even though I didn't test 0cm of wire, it is common sense to assume that 0cm of wire will give 0? in resistance. This graph is a liner graph and it shows clearly that: Length ?

2. Investigate one or more factors affecting the resistance of metal wires

unfortunately, I did not have enough time to take enough readings for different diameters of wire at the same length and at a constant voltage supply. This means that I do not have enough readings to draw a suitable graph.

1. Discover the factors affecting resistance in a conductor.

a thick diameter as well as a thin diameter). I chose the diameters as 2.3 cm, 2cm, 1.5cm, 1.2cm, and 1cm. Also, for the ammeter/voltmeter experiment, the voltage from the power pack will remain constant throughout. 1.5cm, 2.3cm, and 1 cm were for the ammeter/voltmeter experiment. 2 cm and 1.2 cm were for the multimeter.

2. Factors affecting Resistance of a wire

I managed to do this by quickly switching off the power pack supply every time I had recorded my set of readings. I then left the power pack to rest for a small interval of time before switching it on again to record the next set of readings.

1. An investigation of the factors affecting the output of a transformer.

Using this set-up I can then vary the distance between the coils by using the ruler. The power supply will draw power form the mains. It will be set to AC for the reasons explained beforehand. I will vary the voltage by turning off the power supply and changing it, then turning it back on.

2. Investigation into the factors affecting the resistance of wire

This rips if currents reach high levels, preventing possible injury. The power supply will be turned off when clips are removed from wires to prevent the risk of shocks. The current in the wires will also be kept low to prevent heat that could be dangerous and cause the wires to give burns.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to