Current vs Number of wires (finding cross section of a wire)

In summary, the resistance of a wire is equal to the length of the wire divided by the cross-sectional area. When wires are added in parallel, the resistance decreases as the cross-sectional area increases. The slope of the graph represents the change in current over the change in number of parallel lines, which can be used to determine the conductivity constant and ultimately the cross-sectional area of the wire.
  • #1
multiix
15
0

Homework Statement


Using conductivity constant (q=1.45*10^6mA) deduce the cross-Sectional area of the wire from the slope of the Data found in the graph.

Voltage was kept constant 1.00 volts

The wires are each 1m long
After graphing the data the
Current(mA) # of parralel lines
121.4 1
268.8 2
442.2 3
578 4

The equation of the graph is y=.0065x+.2197

Homework Equations


I=qVA/(L)--------- I is current, q is conductivity constant=1/resistivity(p), V is voltage, A is cross sectional area, L is length of the wire.

R=pL/A

R=V/I

The Attempt at a Solution


I was thinking that since the number of wires are increasing and the voltage is constant the resistance is dropping.
I'm not sure what the slope is representing and how i can put it to use in the formulas above.

If someone could please explain. Please let me know if you need any more information.
 
Physics news on Phys.org
  • #2
You have the equation you need to understand this problem. The resistance of a wire

R = rho*L/A

This tell you that the resistance of a wire of a given material is equal to a constant times the length divided by the cross-sectional area of the wire. Double the length of the wire, double the resistance. Double the cross-sectional area of the wire and halve the wires resistance. When you add the wires in parallel the resistance goes down, you are effectively increasing the area of the wire.

You have noticed that the current is nearly proportional to the number of wires?
 

FAQ: Current vs Number of wires (finding cross section of a wire)

1. What is the relationship between the current and number of wires in finding the cross section of a wire?

The current and number of wires have a direct relationship when finding the cross section of a wire. As the number of wires increases, the cross section of the wire also increases. This is because more wires allow for more pathways for the current to flow through, resulting in a larger cross section.

2. How does the current affect the cross section of a wire?

The current has a significant impact on the cross section of a wire. As the current increases, the cross section of the wire also increases. This is because a higher current requires a larger cross section to allow for the flow of electrons without overheating the wire.

3. Is there an optimal number of wires to use when finding the cross section of a wire?

There is no specific number of wires that is considered optimal for finding the cross section of a wire. The number of wires used will depend on the specific application and the desired cross section. Generally, using more wires will result in a larger cross section, but it may also increase the cost and complexity of the wiring system.

4. How do different materials affect the current and number of wires needed to find the cross section of a wire?

The material of the wire will affect the amount of current that can flow through it and the number of wires needed to achieve a certain cross section. Different materials have different conductivities, so a wire made of a less conductive material may require more wires to handle the same amount of current as a wire made of a more conductive material.

5. What are the safety considerations when dealing with the current and number of wires in finding the cross section of a wire?

It is important to consider safety when dealing with the current and number of wires in finding the cross section of a wire. Using wires with a smaller cross section than required for the current can lead to overheating and potentially cause a fire. It is also essential to follow proper wiring practices and use appropriate safety measures when working with electricity to avoid injury.

Similar threads

Finding the voltage drop along a tapered wire
Replies
30
Views
2K
Charge passing through a cross section for a time varying current
Replies
2
Views
3K
Potential Gradient of potentiometer wire
Replies
2
Views
4K
Current through a bound cross-section
Replies
3
Views
3K
Number of Wires & Cross-Sectional Area
Replies
2
Views
2K
Poynting vector of current carrying wire
Replies
8
Views
4K
What is the optimal thickness of a coating to reduce a wire's resistance by 50%?
Replies
6
Views
2K
Wires in an circuit, different materials, heat
Replies
2
Views
998
Finding the power loss in a wire of varying cross-sectional area
Replies
8
Views
2K
Nuclear reactions, cross section, reaction rate
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top