wire with a resistivity of 2 x 10-8 W-m, and a diameter of 1.2 mm to give a resistance of 37.7 W.?

Question

wire with a resistivity of 2 x 10-8 W-m, and a diameter of 1.2 mm to give a resistance of 37.7 W. Length = m

Answer 1

I will assume that your capital 'W' is what you are using for the Ohm symbol.

1. You have resistivity in Ohm-meters.
2. You have a diameter in mm, which can be converted to an area in mm^2 : pi * r^2 = pi * (d/2)^2 make sure the units are in square meters, not square millimeters.
3. Divide the resistivity by the area, then you have Ohms per meter.
4. Divide 37.7 Ohms by the Ohms per meter number you get and you end up with a length in meters.

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Answer 2

Resistance= Resitivity X length of conductor/ go sectional section you have length=2.9 m go sectional are= pie X r X r ( pie=3.14 ), the place r=a million.8/2 Convert r in m and positioned it interior the formula. you will desire the resistivity of copper that would desire to be reported on your question e book.