Question

A coil annealed copper wire has 820 turns, the average of which is 9 in. If the diameter of the wire is 32 mils, calculate the total resistance of the coil at 20 degree Celsius.

Answer 1

Hint:
here we have to apply the subsequent formula:
\[\Large R = \rho \frac{l}{s}\]
where R is the requested resistance, l, is the total length of the coil, and s is the cross sectional area of the coil

Answer 2

\[\rho \] is the specific resistivity, which depends on the temperature of the coil

Answer 3

Note. Insure that your units are compatible with your specific resistivity. Circular mils is based on units in inches. Most values of specific resistivity is based on dimensions based on the metric system.