What Is the Diameter of a Nichrome Wire in a Circuit?

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SUMMARY

The diameter of a 19-cm-long nichrome wire connected to a 1.8 V battery with a current of 2.1 A is calculated to be approximately 0.265 mm. The resistance (R) of the wire is determined to be 0.86 Ohms using the formula R = ρL/A, where ρ (resistivity) for nichrome is 100 x 10^-8 Ω·m. The cross-sectional area (A) is derived from the resistance and subsequently used to find the radius (r), which is then converted to diameter.

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dismalice
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Homework Statement


A 19-cm-long nichrome wire is connected across the terminals of a 1.8 V battery. If the current in the wire is 2.1 A, what is the wire's diameter in mm?


Homework Equations


R = Rho*L
--------
A
v=ir


The Attempt at a Solution


rho for this = 100 e -8.

V=IR
TF,
R = .86 Ohms
100 e -8(.19)
-------------
.86

= 2.21 e -7 m^2

A = pi * r^2

(2.21 e -7/pi)^.5 = r

= 0.000265229118 m.

= 0.265229118 millimeters
 
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Note the question is asking for the wire's diameter, not its radius.
 

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