Calculating Resistance of 0.35m Copper Wire (20 AWG)

In summary: So, with two 1.5 volt AA batteries connected in series, the wire would provide a current of .0312 amps. If you wanted to connect a switch to the wire, it would require a minimum rating of .12 amps.
  • #1
.:Endeavour:.
80
1
I want to know, how do you calculate the resistance of a copper wire with a length of 0.35 meters (1.148 feet) long with a diameter of 0.8118 mm (20 AWG). I found that the resistance of a copper wire in one foot is 98.496 [tex]\omega[\tex] and will be two 1.5V AA battery, so the current running through the wire is going to be approximately 0.031 amps. If If want to connect a switch to the wire, what should be the requirements for the switch or any other electrical devices?

Here is where I got the resistance for the wire with a 20 AWG gage.
http://www.eskimo.com/~billb/tesla/wire1.txt
 
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  • #2
You could use a volt meter and measure the current coming from the source and the then the current after it has flowed through the wire and calculate the amount of current lost using ohms law I=V/R
 
  • #4
.:Endeavour:. said:
I want to know, how do you calculate the resistance of a copper wire with a length of 0.35 meters (1.148 feet) long with a diameter of 0.8118 mm (20 AWG). I found that the resistance of a copper wire in one foot is 98.496 [tex]\omega[\tex] and will be two 1.5V AA battery, so the current running through the wire is going to be approximately 0.031 amps. If If want to connect a switch to the wire, what should be the requirements for the switch or any other electrical devices?

Here is where I got the resistance for the wire with a 20 AWG gage.
http://www.eskimo.com/~billb/tesla/wire1.txt

Per the AWG (American Wire Gauge) listed on the HyperPhysics website, 20 gauge solid copper wire @20 C (68 F) has a resistance of 10.15 ohms per 1,000 feet, which equates to .01015 ohms per foot (.01015 ohms/ft * 1,000 feet = 10.15 ohms).

Per your length of 1.148 feet, that would equate to .0116522 ohms (.01015 ohms/ft * 1.148 feet = .0116522 ohms).
 

1. What is the formula for calculating resistance in a copper wire?

The formula for calculating resistance in a copper wire is R = (ρ * L) / A, where R is resistance in ohms, ρ is the resistivity of copper (1.68 x 10^-8 ohm-meters), L is the length of the wire in meters, and A is the cross-sectional area of the wire in meters squared.

2. How do I determine the cross-sectional area of a 0.35m copper wire with a 20 AWG?

American Wire Gauge (AWG) is a standardized system for determining the diameter of a wire based on its gauge number. To determine the cross-sectional area of a 20 AWG copper wire, you can use the formula A = π * (d/2)^2, where A is the cross-sectional area in meters squared, π is pi (3.14), and d is the diameter of the wire in meters (which can be converted from the AWG using a conversion chart).

3. What is the resistivity of copper?

The resistivity of copper is 1.68 x 10^-8 ohm-meters. This value is a measure of how well a material resists the flow of electricity. Copper has a relatively low resistivity, making it a good conductor of electricity.

4. How does the length of a copper wire affect its resistance?

The longer a copper wire is, the higher its resistance will be. This is because the longer the wire, the more collisions the electrons will experience as they move through the wire, leading to a greater overall resistance.

5. What are the units for resistance in the formula R = (ρ * L) / A?

The units for resistance in this formula are ohms (Ω). This unit is equivalent to volts per ampere (V/A) and is a measure of how much a material resists the flow of electricity.

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