Respuesta :
Answer:
R/l = 0.25925 Ω / m
Explanation:
Ohm's law says that the potential difference is proportional to the product of the resistance by the current
V = I R
R = V / I
In this case, since we have two lengths, we can have two lengths, we can find the resistance for each
L = 5 m
R = 7.70 / 5.47
R = 1,408 Ω
L = 10 m
R = 7.70 / 3.25
R = 2,369 Ω
We can make a direct proportions rule (rule of three) to find the resistance per unit length
For L = 5 m
R/l = 1,408 / 5
R/l = 0.2816 Ω / m
For L = 10 m
R/l = 2,369/10
R/l = 0.2369 Ω / m
We can see that the value is similar that differs from the second decimal place, in this case the value for the longer re wire is more accurate because it has a lower joule effect.
One way also to find the average value
R/l = (0.2816 + 0.2369) / 2
R/l = 0.25925 Ω / m
Answer:
Resistance per unit length = (0.2593 ± 0.022) ohms/m
Explanation:
V = potential difference across the wire of each = 7.7c
Current reading in 5m wire = 5.47A
Current reading across 10m wire = 3.25
Resistance R= V/A
Where v = volt, A = ampere
So
Resistance across 5m wire = 7.7/5.47 =1.408ohms
Resistance across 10m wire = 7.7/3.25 = 2.369ohms
Resistance per unit length of 5m wire =1.408ohms/5 = 0.2816ohms/m
Resistance per unit length of 10m wire = 2.369ohms/10 = 0.2369ohms/m
Range of error between wires = 0.24ohms per m which is acceptable
Average of two tests = 0.2593ohms/m
Lower range = average of test - 5m wire resistance per unit length
=0.0223= upper range
So resistance per unit length of wire =(0.2593 ± 0.022) ohms/m