Homework Help

A stand of wire has resistance 5.60μ Ω. Find the net resistance of 120 such strands...

user profile pic

bc090400375 | Student, Undergraduate | (Level 1) eNoter

Posted January 5, 2011 at 1:37 PM via web

dislike 0 like

A stand of wire has resistance 5.60μ

Ω. Find the net resistance of 120 such strands if they are:Two given options.

 

(b)connected to end to form a wire 120 times as long as a single strand.

1 Answer | Add Yours

user profile pic

ndnordic | High School Teacher | (Level 2) Associate Educator

Posted January 6, 2011 at 6:24 AM (Answer #1)

dislike 0 like

The resistance of any wire is related to its length, cross-sectional area, and the material it is made of.

The general formula is :  R = rho (resistivity)L/A; wher rho is resistivity and is dependent on the material, L (length), and A(cross sectional area).  A = V/L

Since the wire remains the same, the resistivity and the area are constant.  That means that the resistance is proportional to the length squared.

Thus, if the length is increased by a factor of 100, the resistance will also increase by a factor of 100 squared. So the new resistance will be 5.6 x 10^-2 ohms.

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes