How do you find the diameter of a wire

In summary, the conversation is about a question where the voltage, mass, resistivity, and density of a wire are given and the diameter and length need to be found. The equation R=pL/A (where p is resistivity) is given as a hint and it is suggested to find another equation to solve for the radius and then multiply by 2 to get the diameter. Ohm's law is mentioned as a possible equation to use. The conversation also discusses using mass density to find the length and suggests using a conversion to get meters.
  • #1
angiep410
39
0

Homework Statement


I have a question where I'm given the voltage, mass, resistivity, and density of a wire and I need to find the diameter and the length. Can someone show me how to do both of these?


Homework Equations



I have no idea what equation would relate voltage, mass, resistivity, and density to the diameter and length.
 
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  • #2
Heres a hint. R=pL/A (p is rho). Find another equation to this and solve for the radius in A and times that by 2 which will give you your diameter
 
  • #3
The actual question is:
A 17.00 Ω resistor is made from a coil of copper wire whose total mass is 37.0 g. The resistivity of Cu is 1.68×10-8 Ω · m and its mass density is 8.90×103 kg/m3. What is the diameter of the wire?

So would I use Ohm's law V=IR to find I?
 
  • #4
Im not totally sure but, you are given the mass density (kg/m^3). If you can find a way to get a length out of that (meters), you can use the formula I gave you and solve for A.
A=4∏r^2, then solve for r and times that by 2
 
  • #5
How should I get a length out of the density?
 
  • #6
Try 1 m^4/ mass (kg) units will cancel out leaving you with m
 

1. How do you measure the diameter of a wire?

To measure the diameter of a wire, you will need a caliper or micrometer. Place the wire between the jaws of the measuring tool and gently close the jaws until they are snug against the wire. Take note of the measurement displayed on the tool. This will give you the diameter of the wire in millimeters or inches.

2. What is the standard unit of measurement for wire diameter?

The standard unit of measurement for wire diameter is either millimeters (mm) or inches (in). Some countries may also use gauge (ga) as a unit of measurement, which is a measurement of the wire's thickness.

3. How accurate is the measurement of wire diameter using a caliper or micrometer?

The accuracy of the measurement will depend on the precision of the measuring tool being used. Generally, a caliper or micrometer can give a measurement accuracy of up to 0.001mm or 0.0001in. However, the accuracy may also be affected by the condition of the wire, such as irregularities or bends.

4. Can wire diameter be determined by measuring the circumference?

Yes, wire diameter can be determined by measuring the circumference and using a mathematical formula. The formula for calculating the diameter from the circumference is diameter = circumference / π. However, this method may not be as accurate as directly measuring the diameter with a caliper or micrometer.

5. What factors can affect the accuracy of wire diameter measurement?

Aside from the precision of the measuring tool, factors that can affect the accuracy of wire diameter measurement include the condition of the wire, the skill of the person taking the measurement, and external factors such as temperature and humidity. It is important to take multiple measurements and calculate the average to get a more accurate result.

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