resistance in a wire by cazzie | Teaching Resources
Cost Disadvantages Independent of Size Apple has a number. A single cable - the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message. Figure 2: Bus topology Source Ethernet bus topologies are relatively easy to install and don 't require much cabling compared to the alternatives.
The problem with using resistance as a measurement is that it depends not only on the material out of which the wire is made, but also the geometry of the wire. If we were to increase the length of wire, for example, the measured resistance would increase. Also, if we were to decrease the diameter of the wire, the measured resistance would increase.
We want to define a property that describes a material's ability to transmit electrical current that is independent of the geometrical factors. In the case of the wire, resistivity is defined as the resistance in the wire, multiplied by the cross-sectional area of the wire, divided by …show more content…. Not all materials are created equal in terms of their conductive ability.
Some materials are better conductors than others and offer less resistance to the flow of charge. Silver is one of the best conductors, but is never used in wires of household circuits due to its cost. Copper and aluminum are among the least expensive materials with suitable conducting ability to permit their use in wires of household circuits. The conducting ability of a material is often indicated by its resistivity.
The resistivity of a material is dependent upon the material's electronic structure and its temperature. For most but not all materials, resistivity increases with increasing temperature.
- narrative scholarship essay.
- cover letter for culinary student;
- photo essay on poverty in america.
The table below lists resistivity values for various materials at temperatures of 20 degrees Celsius. Those materials with lower resistivities offer less resistance to the flow of charge; they are better conductors. The materials shown in the last five rows of the above table have such high resistivity that they would not even be considered to be conductors.
There is another important property that can be measured in electrical systems. This is resistance, which is measured in units called ohms. Resistance is a term that describes the forces that oppose the flow of electron current in a conductor. All materials naturally contain. Show More. Read More. Hows does changing the length of wire affect resistance? How Does Length Affect Resistance?
I can get a reading for a cm, I got 0.
Physics Coursework Essay
For 10cm though I can only get a voltmeter reading of 0. The current is too high for the meter to measure. So I have decided to change my ammeter to one that goes up to 5 amps instead of 1.
On the new ammeter I still get the same readings for a cm as before. But I now get a reading for 10cm of being 0. Resistivity gives a constant value for a material, so that you can compare different materials. The resistance of 2 different wires is not necessarily the same. Resistance depends on:. So to my results tables I have added the column length divided by area which is the other part that I need to work this out as well as the resistance. In working out my averages for resistance I decided to leave out the result I got for cms of wire on my 2nd repeats 5.
I have now worked out the average resistance and the average length divided by area. So I now have everything I need to compare my results to the figures I got from the book. My results show me that the longer the piece of wire is, the more resistance there will be. This is what I predicted would happen in my prediction.
I think this happened because the more wire there is the more particles there are to bang into, which slows down the electrons.
Resistance of a Wire Experiment
I also found that Resistance and Length are proportional, I could tell this by the straight line of best fit that I got on my first graph. From my 2nd graph I took the gradient of the line of best fit this represented the Resistivity of a constantan wire. I got 0. Comparing these figures I would say that my results were quite accurate as the difference is 0. From my method I was able to easily achieve a set of results. I think that the method I chose to use was quite reliable. If I were to do this investigation again I would come up with a better way of doing it though to get more accurate results because the wire kept bending so I am not sure that the distances we measured at were very precise.
As I mentioned before I think that I only had one anomaly and did not use this in working out my averages. I think we got this anomaly because near to the end of the investigation we started to rush becoming a bit more careless, maybe living the power pack on which would of increased the resistance because the wire would have been hotter.
Physics Coursework. Accessed October 18, We will write a custom paper sample on Physics Coursework specifically for you.
Related resistance in the wire coursework
Copyright 2019 - All Right Reserved