# Resistance in a Wire (coursework Evaluation)

• Jozers
In summary, Jozers is seeking suggestions for an alternative experiment related to the length of a wire and its resistance. They have already calculated resistance using ohm's law and are looking for ways to control the resistance, possibly through a variable resistor. They must keep in mind that the experiment must relate to length and not wire temperature or cross-sectional area. Suggestions include using a slide wire rheostat or researching the Wheatstone bridge.
Jozers
To get the full marks for my gcse coursework "how does length affect the resistance in a wire?" I need to provide an alternative experiment that I could perform if I were to redo the investigation. I have already calculated resistance in circuit using ohm's law and predicted results using the R=ρL/A. Does anyone have any suggestion to what I could do? I haven't had any luck researching this, although my teacher hinted that I could do something with variable resistor to control the resistance but I have no idea how. Please remember this must relate to the length not wire temperature or cross-sectional area.

Thanks
Jozers

Jozers said:
To get the full marks for my gcse coursework "how does length affect the resistance in a wire?" I need to provide an alternative experiment that I could perform if I were to redo the investigation. I have already calculated resistance in circuit using ohm's law and predicted results using the R=ρL/A. Does anyone have any suggestion to what I could do? I haven't had any luck researching this, although my teacher hinted that I could do something with variable resistor to control the resistance but I have no idea how. Please remember this must relate to the length not wire temperature or cross-sectional area.

Thanks
Jozers
Have you ever used one of those big slide wire rheostats as a variable resistor?

http://www.thesciencefair.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=1856-2&Category_Code=ET

Knowing how it works might give you some ideas. You might also want to find out about the Wheatstone bridge if you have not already encountered it.

Last edited by a moderator:

I would suggest that you could perform an experiment using different materials for the wire. This would allow you to investigate how the material of the wire affects its resistance and how it compares to the results obtained from changing the length of the wire.

To do this, you could use wires made of different materials such as copper, aluminum, and nichrome. You can then measure the resistance of each wire at different lengths and compare the results. This will provide a more comprehensive understanding of how the material of the wire affects its resistance, in addition to the length.

Another alternative experiment could be to investigate the effect of temperature on resistance in a wire. To do this, you could use a variable resistor to control the temperature of the wire and measure the resistance at different temperature levels. This will allow you to see how temperature affects the resistance of the wire and how it compares to the results obtained from changing the length.

Furthermore, you could also explore the effect of wire thickness on resistance by using wires of different diameters. This will allow you to investigate how the cross-sectional area of the wire affects its resistance and how it compares to the results obtained from changing the length.

In conclusion, there are many alternative experiments that you could perform to investigate the relationship between length and resistance in a wire. The key is to vary one factor at a time while keeping others constant, and to compare the results to gain a deeper understanding of the factors that affect resistance in a wire.

## 1. What is resistance in a wire?

Resistance in a wire is the measure of how difficult it is for an electric current to flow through a wire. It is caused by collisions between the moving electrons and the atoms of the wire, which creates friction and slows down the flow of current.

## 2. How is resistance in a wire measured?

Resistance is typically measured in units of Ohms (Ω) using a device called a multimeter. The wire is connected to the multimeter and a small amount of current is passed through it. The multimeter then measures the voltage drop across the wire and uses Ohm's Law (V = IR) to calculate the resistance.

## 3. What factors affect the resistance of a wire?

The resistance of a wire is affected by its length, cross-sectional area, material, and temperature. Longer wires have higher resistance because there is more distance for the electrons to travel and collide with atoms. Thicker wires have lower resistance because there is more space for the electrons to flow. Different materials have different resistances, with metals having lower resistance than non-metals. As the temperature of a wire increases, the resistance also increases due to increased atomic vibrations.

## 4. How does the resistance of a wire impact its performance in an electrical circuit?

The resistance of a wire impacts its performance in an electrical circuit by affecting the flow of current. A higher resistance means that more energy is lost as heat, which can cause the wire to overheat and potentially fail. It can also limit the amount of current that can flow through the wire, which can affect the functioning of the circuit.

## 5. How can the resistance of a wire be reduced?

The resistance of a wire can be reduced by using a shorter and thicker wire made of a highly conductive material. Lowering the temperature of the wire can also decrease its resistance. In some cases, the wire can also be coated with a material that has lower resistance, such as silver or copper, to reduce its overall resistance.

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