Answer:
1 x 10⁻¹¹m²
Explanation:
Given parameters:
Resistivity = 100 x 10⁻⁶Ohm.m
Cross-section = 1mm²
Resistance = 10ohm
Unknown:
length of the nichrome wire = ?
Solution:
To find the length of the nichrome wire, we use the expression below:
L = \frac{RA}{P}PRA
where l is the length of the wire
R is the resistance of the wire
A is the area
p is the resistivity
Now we need to convert area from mm to m;
1000mm = 1 m
1mm² = 1 x \frac{1m}{1000mm} x \frac{1m}{1000mm}1000mm1mx1000mm1m = 1 x 10⁻⁶m²
Input the values in the formula;
L = \frac{100 x 10^{-6} x 1 x 10^{-6} }{10}10100x10−6x1x10−6 = 1 x 10⁻¹¹m²
