- #1
MisterP
- 47
- 3
Homework Statement
Need to calculate, how many turns of nichrome wire do I need on a cylinder to make a heater with resistance of 40 Ω.
Wire diameter = 1mm
Cylinder radius = 2.5cm
R = 40 Ω
Wire diameter = 1mm
Correct answer - 200 turns
Homework Equations
R = ρ*l/S
R = resistance
ρ = specific resistance (I guess) and it is 1.1 Ω⋅mm2/m
l = length of wire
S = area of wire "cross section"
The Attempt at a Solution
Area of wire = Π*r2 = 3.14 * 0.52 = 0.785mm2
So I used this formula, but get nowhere close to 200 turns. 40 = 1,1l/0,785...